(CNN) President Donald Trump's immigration policies have drawn both widespread praise and condemnation since he took office less than two months ago.
The administration's latest move -- a temporary suspension of the expedited processing of H-1B visas -- comes as the Trump White House tweaks a court-halted executive order that banned travelers from seven Muslim-majority countries from entering the United States.
The controversial ban led to massive protests at airports across the country after travelers with valid visas were detained. The new ban will exclude existing visa holders, sources familiar with the plan have told CNN.
The revamping of the H-1B program is part of Trump's pledge to crack down on the misuse of work visas.
Here's what you need to know about the visa program:
The visa is the popular pathway for high-skilled foreigners to work at companies in the United States.
Long embraced by the tech community, the program has many talented engineers vying for one of the 85,000 visas each year.
Companies ranging from health care to media use H-1B visas to help fill their workforces.
But tech companies are most commonly associated with the program.
Tech firms of all sizes claim they need the H-1Bs to hire trained talent they can't find at home.
The visas are doled out by a lottery, and the number of applicants continues to swell each year.
Outsourcing firms flood the system with applicants, obtaining visas for foreign workers and then farming them out to tech companies. They take a sizable cut of the salary.
Under the current system, companies submitting applications for H-1B visas for potential employees can pay extra for expedited processing, which is referred to as premium processing.
Premium processing costs an additional $1,225 and ensures a response from the US Citizenship and Immigration Services in 15 days or the fee is refunded.
Processing of standard H-1B applications -- those that are not premium -- takes between three and six months.
The suspension on expedited visas becomes effective April 3 and could last up to six months, according to the agency.
The visas enable foreign workers with special skills and tech know-how to showcase those talents at US companies, hospitals and other institutions. The visas help not only the economy but society overall.
Rosario Marin, former US treasurer under President George W. Bush, called for the expansion of the H-1B program in an opinion piece for CNN last year.
She wrote of the overwhelming demand from American companies for educated, skilled foreign workers to fill jobs in computer programming, coding, medicine and information technology.
"These are jobs that would be left largely unfilled if not for international workers, as our domestic workforce doesn't consist of graduates with these skills in the enormous numbers we require," wrote Marin, co-chair of the American Competitiveness Alliance, a coalition of organizations dedicated to advancing immigration reform.
Marin described H-1B as "a cornerstone of the American economic system."
"Without them, companies struggle to locate the specific people with the specific computer and science skills they need to grow, translating into an inability to expand, to create jobs, to scale up. The United States must work to address our shortage of students graduating with advanced science, math and technology skills, but until it does, American companies need high-skilled international workers, not only to compete, but to survive."
A common complaint among critics of the program is that some companies use H-1B visas to get cheap foreign labor. As a result, startups can lose out to big outsourcing firms, which are able to gobble up a disproportionate share of the visas.
The vast majority of H-1B holders have only bachelor's degrees.
At the three companies with the most H-1B employees, 80% of visa holders possess only bachelor's degrees, according to Ronil Hira, an associate professor at Howard University who studies the H-1B program and outsourcing industry.
Critics maintain that people with bachelor's degrees are not necessary to fill the so-called skills gap and that they are just taking jobs from Americans.
Of the 85,000 visas handed out annually, 20,000 are reserved for people with advanced degrees.
Other critics fear that H-1Bs pave the way for cheap foreign labor despite safeguards that should theoretically prevent that from happening.
Employers must pay visa holders, at a minimum, a job's prevailing wage, which varies by job description and location.
A group of professors studying how H-1B holders affect the economy said wages for US computer scientists were lower in 2001 as a result of the influx of the visa holders. They used data from the dot-com bubble between 1994 and 2001.
In addition, the existing H-1B program doesn't exactly work in favor of entrepreneurs with fledgling companies.
Some startups don't bother applying on behalf of prospective employees because of the costs. And there are no guarantees of a pick in the lottery. It's impossible to compete with the big tech companies and offshoring firms that often submit a huge amount of applications, entrepreneurs argue.
Immigrants who want to start companies also can have a hard time with the current system.
In 2015, some 233,000 visas were requested, according to the US Citizenship and Immigration Services, far exceeding the 65,000 general-category cap and the 20,000 advanced-degree cap.
There's no prioritization within the lottery system, which means many of the most highly educated workers could be turned away.
"This is the heart of the issue that legislators have begun to tackle: how to prioritize who should get the H-1B visa and also to make sure Americans are not displaced by workers brought in by the visa program," said Neil Ruiz, executive director of the Center for Law, Economics and Finance at the George Washington University Law School.
Yes. The US employer must offer the employee a permanent job in the United States. The green card process requires the employer to file a certification with the Department of Labor before filing a petition with the Citizenship and Immigration Services. The processing time is lengthy, and H-1B workers are allowed to extend their status past the six years normally allowed, but only if they have reached a certain stage in the green card process.
The Citizenship and Immigration Services says the suspension, which may last up to six months, will help it reduce overall H-1B processing times.
The agency says it has been unable to process long-pending petitions because of the high volume of new petitions and a significant surge in expedited processing requests in recent years.
The temporary suspension applies to all H-1B petitions filed on or after April 3.
A new bipartisan bill introduced this week in the House of Representatives is taking aim at H-1B and other popular visa programs.
The legislation would replace the lottery with a "preference system," giving priority to foreign students educated in the United States. It aims to help weed out foreign outsourcing firms, which critics say exploit the system.
In addition, employers would be required to make a "good faith effort" to recruit American workers over foreigners and give the Homeland Security and Labor departments more authority to investigate fraud and abuse.