(CNN) US Vice President Mike Pence will meet with Venezuela's self-declared interim president and opposition leader, Juan Guaido in Bogota, Colombia Monday, following a weekend of violent clashes along Venezuela's borders with Colombia and Brazil.
Latest developments
Deaths and injuries: Nearly 300 people are estimated to have been injured in clashes between Venezuelan troops loyal to President Nicolas Maduro and protesters in areas near the country's border over the weekend. The opposition says five people were also killed. CNN has not verified those numbers.
Aid deliveries: Trucks carrying supplies were stopped at most spots Saturday. Witnesses said two trucks were set ablaze while attempting to cross into Venezuela from Colombia.
US response: US Secretary of State Mike Pompeo condemned the actions of Maduro's government and said the US would "take action against those who oppose the peaceful restoration of democracy in Venezuela." Pompeo wrote on Twitter: "What kind of a sick tyrant stops food from getting to hungry people? The images of burning trucks filled with aid are sickening."
Tensions with Colombia: Maduro on Saturday told supporters he was breaking all diplomatic relations with Colombia and calling for its ambassadors and consuls to leave Venezuela. Colombia ordered its diplomats to leave immediately for their safety.
Defections: Colombia's customs agency said Sunday that 104 members of Venezuela's security forces had defected, entering Colombia.
US will offer Guaido 'unwavering support'
While in Colombia, Pence will also address a meeting of the Lima Group -- a diplomatic body created by leaders mostly from Latin American countries to help mitigate the Venezuelan crisis.
The White House said Pence would "voice the United States' unwavering support for interim President Juan Guaido and highlight the Venezuelan people's fight for democracy over dictatorship."
Guaido, who arrived in Bogota Sunday, is battling President Nicolas Maduro for control of Venezuela. He has called for other nations to send aid to the country in response to worsening food and medicine shortages. But Maduro -- who won re-election in a widely-criticized vote last year -- denies that a humanitarian crisis exists in Venezuela and suggests that aid efforts are part of a US plot to orchestrate a coup.
The dispute led the Venezuelan military -- on Maduro's order -- to block aid convoys at the country's border on Saturday.
Trucks set ablaze during aid attempt Saturday
Trucks carrying supplies were stopped at most spots Saturday. Witnesses said two trucks were set ablaze while attempting to cross into Venezuela from Colombia.
CNN cannot independently confirm the incident or the circumstances of how the two trucks were set on fire.
Venezuelan Communications Minister Jorge Rodriguez accused Guaido supporters of burning the trucks.
While a CNN team saw incendiary devices from police on the Venezuelan side of the border ignite the trucks, the network's journalists are unsure if the trucks were burned on purpose.
In photos: Venezuela in crisis
Supporters of Venezuelan opposition leader Juan Guaido wave a Venezuelan flag as they wait for him to make an appearance in the country's capital of Caracas on Monday, March 4.
Guaido greets supporters upon arriving at a Caracas airport on March 4. He crossed the border to Colombia in late February before embarking on a South American tour, meeting the presidents of Colombia, Brazil, Paraguay and Ecuador, along with US Vice President Mike Pence. By doing so, Guaido
ignored a travel ban imposed on him by the country's Supreme Court.
Guaido shakes hands with Pence in Bogota, Colombia, on Monday, February 25. The room was filled with humanitarian aid destined for Venezuela. Guaido's wife, Fabiana Rosales, is pictured at left.
Demonstrators clash with Venezuelan soldiers at the Simon Bolivar International Bridge in Cucuta, Colombia, on Saturday, February 23.
Supporters of President Maduro take part in a march in Caracas on February 23.
Guaido supporters take part in a march in Caracas on February 23. Venezuelan security forces fired tear gas and rubber bullets to disperse a crowd demanding to cross the Venezuela-Colombia border, which was ordered closed by Maduro.
Demonstrators push a bus that was set on fire during clashes with the Venezuelan National Guard in Urena, Venezuela, on February 23.
Maduro waves the national flag during a pro-government march in Caracas on February 23. During the rally at the Venezuelan capital, Maduro told supporters he is breaking all diplomatic relations with Colombia and is calling for its ambassadors and consuls to leave Venezuela. Maduro recently began a second term after a 2018 vote that his political opposition and many in the international community denounced as a sham.
People attempt to salvage packages from a truck loaded with humanitarian aid after it was set ablaze on a bridge between Cucuta, Colombia, and Urena, Venezuela, on February 23.
Venezuelan opposition supporters protested in Caracas on Tuesday, February 12, calling on Maduro to let humanitarian aid into the economically crippled country.
Guaido addresses the crowd in Caracas on February 12.
A man wearing a Venezuelan flag sits on a traffic light during the demonstration in Caracas on February 12.
Guaido waves to supporters during the rally in Caracas on February 2.
An anti-government protester wears glasses with a Venezuelan flag motif at the demonstration in Caracas on February 2.
Protesters gather for the Caracas rally on February 2.
Maduro supporters gather in Caracas on February 2.
Opposition demonstrators protest against Maduro's government on Wednesday, January 30.
In this handout photo released by the Miraflores Presidential Press Office, Maduro flashes a "V for victory" hand gesture after arriving at the Fort Tiuna military base in Caracas on January 30.
Members of the National Police line up to guard the entrance of Venezuela's Central University in Caracas during an anti-government protest on January 30.
Guaido speaks to reporters in Caracas on January 30. The United States and more than a dozen other countries have recognized Guaido as Venezuela's legitimate ruler.
A Maduro mural is seen in the Petare slum of Caracas on Tuesday, January 29.
Guaido listens to deputy Rafael Veloz during a session at the National Assembly in Caracas on January 29. The Assembly met to debate a legal framework for creating a transitional government and calling new elections. Simultaneously, Venezuela's attorney general asked the Supreme Court to freeze Guaido's assets and bar him from leaving the country.
A view of the National Assembly building in Caracas on January 29.
The president of Venezuela's Supreme Court, Maikel Moreno, speaks at a news conference in Caracas on January 29.
A man pumps fuel at a gas station in Caracas on January 29. A day earlier, the United States announced sanctions against Venezuela's state oil company, Petroleos de Venezuela, S.A.
Supporters of Venezuela's opposition hold up letters that read "Justice" at a rally to hear Guaido speak in Caracas on Saturday, January 26.
Guaido speaks to reporters after attending Mass in Caracas on Sunday, January 27.
Government supporters in Caracas hold a rally in support of Maduro on January 26.
Maduro holds a news conference in Caracas on Friday, January 25. The Venezuelan strongman has accused Guaido and the United States of trying to orchestrate a coup against him.
Portraits of former Venezuelan leaders Simon Bolivar and Hugo Chavez hover in the background as Venezuelan Defense Minister Vladimir Padrino Lopez, bottom left, addresses a news conference in Caracas on Thursday, January 24. Venezuela's top military officials swore their allegiance to Maduro after other nations recognized Guaido as head of state.
A man wrapped in a Venezuelan flag raises his arms in front of security forces during anti-government protests in Caracas on Wednesday, January 23.
Opposition supporters in Caracas protest Maduro on January 23.
Opposition supporters react to tear gas as they take part in the Caracas rally on January 23. Sporadic clashes erupted, but Maduro's military response to the protests seemed more measured than in the past.
Police secure an area in Caracas on January 23.
A National Police officer fires rubber bullets in Caracas.
People raise their hands to show solidarity with Guaido, who was declaring himself interim president on January 23.
A wounded protester in Caracas on January 23.
Security forces stand in a street full of stones after clashing with demonstrators in Caracas.
Maduro, speaking to a crowd of supporters at the Miraflores Palace in Caracas, holds up a document that says his government is breaking off diplomatic ties with the United States. "We cannot accept the invasive policies of the empire, the United States, the policies of Donald Trump," he said to cheers from the crowd on January 23. "Venezuela is a land of liberators."
A wounded protester shows his back as riot police clashed with opposition demonstrators in Caracas on January 23.
A man walks by a bus that had been set on fire in Caracas.
An opposition demonstrator runs with a tear-gas canister on January 23.
Guaido greets a crowd in Caracas on January 23.
Protesters set up barricades to block a road in Caracas.
A National Police officer fires tear gas at demonstrators in Caracas while another shoots the scene with a cell phone.
Demonstrators in Caracas protest Maduro's government.
Venezuelan banknotes were thrown on the ground during the Maduro protests on January 23.
Humanitarian aid moved through the Brazilian-Venezuelan border in Pacaraima, according to Maria Teresa Belandria, Venezuela's opposition-appointed ambassador to Brazil.
Workers blocked from entering Colombia
Venezuelan soldiers faced off against protesters who were demanding to cross the border at Ureña to go work in Colombia, according to a CNN crew that witnessed the scene at the Tienditas Bridge.
The Colombian foreign minister said 285 people were hurt, with 37 requiring hospitalization, after the Venezuelan National Guard fired tear gas and rubber bullets at protesters near the Colombian border Saturday.
The Venezuelan Government's special envoy for the Tachira State -- which borders Colombia -- said Sunday more than 300 people were injured Saturday.
"The Bolivarian forces registered 315 injured, some by firearm others by Molotov cocktails," envoy Freddy Bernal said. "We registered no deaths despite the violent attacks for more than 15 hours of battle" by groups on the international bridges fighting "against thousands of patriots who fought and defended themselves."
Bernal did not specify whether the injured toll includes members of the National Guardsmen, or strictly civilians fighting alongside the National Guard. CNN has not independently verified the numbers of the injured in these clashes.
Reports of fatalities
National Assembly Representative and Guaido supporter Adriana Pichardo told CNN that at least five people were also killed in clashes with Venezuelan security forces.
Juan Guaido with Colombian Foreign Minister Carlos Holmes Trujillo in Bogota Sunday.
CNN cannot independently confirm the number of fatalities, but Michelle Bachelet, the UN high commissioner for human rights, said there were four deaths and 300 injuries Friday and Saturday.
CNNE crews heard shots beings fired and saw tear gas being thrown in the Brazilian-Venezuelan border town of Pacaraima, Brazil Saturday.
The governor of Roraima, the Brazilian state bordering Venezuela, declared a state of medical emergency on Sunday, according to a press release from the Roraima Ministry of Health.
Governor Antonio Denarium is quoted in the release saying the state's largest hospital, in the capital Boa Vista, is "at the brink of collapse" following the influx of victims injured in clashes across the border in Venezuela.
Rocks and rubber bullets in Sunday clashes
Sunday was quieter. Small clashes broke out again at a town near the border with Colombia. CNN's team in Ureña, Venezuela, saw dozens of people throwing rocks toward Venezuela's National Guard, who fired back with rubber bullets. There was no report on injuries.
Rodriguez said that the country's security forces had protected the border in "exemplary" fashion.
But Bachelet, the UN official, described "disgraceful scenes." "The Venezuelan government must stop its forces from using excessive force against unarmed protesters and ordinary citizens," she said.
In a statement Sunday, UN Secretary General António Guterres said he is "following with increasing concern" the tensions in Venezuela.
Guterres called "for violence to be avoided" and "for lethal force not to be used in any circumstances."
Maduro defiant
Meantime, Colombia's customs agency said Sunday that 104 members of Venezuela's security forces have defected, entering Colombia. The development is a sign that Maduro's grip on the military -- control of which is seen as integral to forcing new elections -- could be waning.
But Maduro put out a defiant message Sunday.
"The people are united in the streets, mobilized and alert in every corner of the country," he said on Twitter. "I call on men and women of goodwill, not to lower their guard and to stay in the fight to preserve Venezuela's peace. Long live the Rebel homeland!"
CNN's Jackie Castillo, Ralph Ellis, Laura Smith-Spark, Jorge Luis Perez Valery, Claudia Dominguez, Christina Maxouris, Natalie Gallon, Eliott C. McLaughlin and Isa Soares contributed to this report.