US national security advisor Jake Sullivan has vowed there would be "real costs" for China if the country went forward with providing lethal aid to Russia in its war on Ukraine.
"From our perspective, actually, this war presents real complications for Beijing. And Beijing will have to make its own decisions about how it proceeds, whether it provides military assistance," Sullivan said on CNN's State of the Union.
"But, if it goes down that road, it will come at real costs to China. And I think China's leaders are weighing that as they make their decisions."
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In diplomatic conversations with China, he added, the US is "not just making direct threats. We're just laying out both the stakes and the consequences, how things would unfold. And we are doing that clearly and specifically behind closed doors."
Sullivan's comments come at a critical juncture in the war in Ukraine.
The US has intelligence that the Chinese government is considering providing Russia with drones and ammunition for use in the war, three sources familiar with the intelligence told CNN.
It does not appear that Beijing has made a final decision yet, the sources said, as negotiations between Russia and China about the price and scope of the equipment are ongoing.
Since invading Ukraine, Russia has repeatedly requested drones and ammunition from China, the sources familiar with the intelligence said, and Chinese leadership has been actively debating over the last several months whether or not to send the lethal aid, the sources added.
"I can level with the American people in saying that war is unpredictable," Sullivan said today when asked if the US could continue supporting Ukraine at current levels a year from now.
"One year ago, we were all bracing for the fall of Kyiv in a matter - in a matter of days. One year later, Joe Biden was standing with President Zelensky in Kyiv declaring that Kyiv stands."
"So, I cannot predict the future, and nor can anyone else. And anyone who is suggesting they can define for you how and when this war will end is not leveling with the American people or anyone else," he said.
Sullivan also reiterated Biden's remarks on Friday that the administration was ruling out providing F-16 fighter jets to Ukraine "for now."
"This phase of the war requires tanks, infantry fighting vehicles, armoured personnel carriers, artillery, tactical air defense systems, so that Ukrainian fighters can retake territory that Russia currently occupies," Sullivan said.
"F-16s are a question for a later time."
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