(CNN) One man started the brutal war in Ukraine and only one man can end it: Vladimir Putin.
The Russian President's escalation of his vicious onslaught over the weekend -- taking the conflict close to NATO territory in Poland and pouring missiles and artillery into civilian areas blighted by a worsening humanitarian crisis -- suggest he's nowhere near ready for a ceasefire.
In fact, the war is only becoming more dangerous and closer to spilling out of control after Moscow told the US it would target Western arms shipments to the Ukrainian armed forces that have helped slow the Russian advance. Ukrainian President Volodymyr Zelensky warned Sunday night that it was only a matter of time before Russian missiles fell on NATO territory -- as he renewed his call for the alliance to close the skies over his country.
While some comments from Ukrainian, Russian and US officials raised the possibility of progress in negotiations between Kyiv and Moscow, which are due to resume Monday, Putin defied an appeal from French President Emmanuel Macron and German Chancellor Olaf Scholz on Saturday for an immediate ceasefire. And there is every sign that the Russian leader, despite presiding over an invasion that has turned Russia into an economic and diplomatic pariah, plans to callously press on and destroy Ukraine to further his personal ambition of preventing it ever joining the West.
The agony of Ukrainian civilians is only getting worse. An already appalling situation is deteriorating in the besieged city of Mariupol, where city officials said more than 2,000 civilians have died. There is no electricity, water or heat and people are running out of food and water. There are also reports of extensive damage in the cities of Kharkiv, Mykolaiv, Dnipro, Chernihiv and Sumy, which have been under relentless Russian bombardment. And an American journalist and filmmaker, Brent Renaud, was killed by Russian forces on Sunday, police in Kyiv said, while another American journalist was wounded. The exact circumstances of the attack are yet to be determined.
None of these developments suggest the war is approaching a point where ceasefire negotiations or peace talks might succeed. And the risks of a wider conflict appear to be deepening.
In fact, the story of the invasion, which was for its early days dominated by the heroic resistance of the outnumbered Ukrainians and Zelensky, appears to be taking a dark turn. Putin seems impervious to the human toll his actions have wrought in a conflict that may be critical to his own capacity to stay in power in Moscow.
In another new dimension to what is threatening to become a broader geopolitical showdown, the United States warned China that it must not provide a "lifeline" to help Russia evade sanctions strangling its economy over its brutal invasion, ahead of crucial talks between senior US and Chinese officials in Europe on Monday.
Speaking on CNN's "State of the Union" on Sunday, White House national security adviser Jake Sullivan spelled out a stark message to Beijing, which has not yet shown any sign of leaning on the Russian leader to end the war. He told Dana Bash that Washington was "watching closely to see the extent to which China actually does provide any form of support, material support or economic support, to Russia."
"We are communicating directly, privately to Beijing that there will absolutely be consequences for large-scale sanctions evasion efforts or support to Russia to backfill them," Sullivan said. "We will not allow that to go forward and allow there to be a lifeline to Russia from these economic sanctions from any country anywhere in the world." Sullivan, who will meet Chinese counterpart in Rome on Monday, did not say whether Chinese firms or government entities would face sanctions if they helped Russia.
The rationale for the warning became clear when a senior US official said Sunday that Russia had asked China for military assistance, including drones. Russia also asked for economic support, according to another US official familiar with the matter who declined to detail the Chinese reaction but indicated that they had responded.
When asked by CNN about the reporting of Russia's request for military aid, Liu Pengyu, spokesperson for the Chinese embassy in the US, said in a statement, "I've never heard of that."
The request could be read as a sign of increasing Russian desperation. Any Chinese aid to Moscow would also magnify the strategic significance of the war in Ukraine and could enshrine the long-time US nightmare of a strategic compact between Beijing and Moscow at a time when China is looming as America's major superpower rival of the 21st century. Before the invasion, Putin traveled to China to meet President Xi Jinping, where the two sides agreed to a friendship with "no limits." There were reports the Russian leader pledged not to invade Ukraine until the end of the recent Beijing Winter Olympics. Some Western officials hope that China will use its newfound influence to help end the war. But in recent days, Beijing's official media has magnified false Russian propaganda that the US has a chemical and biological weapons lab in Ukraine, which US officials fear could be a precursor to the use of such weapons by Russia in the war.
There is no publicly available indication that Beijing is helping Putin's war effort -- and there are reasons why China may not see its interests as fully mirroring Moscow's in this situation. It is widely assumed that Xi will secure a historic third term in power during the Communist Party's 20th National Congress in Beijing this fall. During such an important year, the Chinese government could be wary of its firms facing knock-on sanctions. Spiking oil prices could, in the long term, damage its economy at a time when its runaway growth rates are slowing.
Western and international sanctions have pitched the Russian economy and banking system into a deep crisis, but the extreme pain they will inflict may not come quickly enough to save Ukraine from Putin's relentless barrage. Any Chinese aid, if it happened, could weaken the Western chokehold on the Russian economy and ease political pressure on Putin for a change of course.
Putin is intensifying his bombardment of Ukraine rather than stepping back.
In an alarming new expansion of the war, Russian missiles fired from planes over the Black and Azov seas hit a military base near Lviv, killing at least 35 people on Sunday, local authorities said. The target was perilously close to the border of NATO member Poland. While President Joe Biden has said he will not send US troops to Ukraine, he has vowed to defend "every inch" of the western alliance's territory.
In another sign of Putin's aggressive intent, after more than three weeks being bogged down in the country, his troops were within 15.5 miles of the capital Kyiv, according to British intelligence on Saturday.
There were conflicting signs in Europe and Washington on Sunday about the prospects of talks between Russian and Ukrainian officials, which so far have yielded little progress, as well as about a broader international diplomatic effort to get Putin to agree to a ceasefire. US Deputy Secretary of State Wendy Sherman argued on Fox on that the pressure from sanctions was beginning to have an effect on the Russian leader.
"We are seeing some signs of a willingness to have real serious negotiations," Sherman said. But she added: "It appears that Vladimir Putin is intent on destroying Ukraine." Sullivan was downbeat on the prospects for diplomacy on "State of the Union," saying Putin "does not look like he is prepared to stop the onslaught."
Still, Ukrainian presidential adviser Mykhailo Podoliak said he thinks talks could "achieve concrete results" in the next few days since Russia has started to talk "constructively." And Leonid Slutsky, a Russian delegation member for the talks, said "significant progress" has been made in negotiations with the Ukrainian delegation since they began, Russian state news agency RIA reported.
But the sides appear far apart in principle -- with Ukraine demanding a withdrawal of Russian troops. Moscow went into the conflict calling on NATO to pull back troops from former Warsaw Pact states in eastern Europe, which is even less likely now given Russia's treatment of Ukraine.
And nothing Putin has done so far suggests that he is contemplating a reversal of a plan that has laid waste to vast areas of Ukraine and now appears to be zeroing in on Kyiv for the decisive battle.