China hasn't yet provided weapons to Russia in Ukraine, but doing so would be 'real mistake': Sullivan

Following warnings from the Biden administration that China is weighing whether to provide Russia with lethal aid for their war in Ukraine, the White House's national security adviser said Sunday that "at this point" they have "not seen them take the step of providing weapons" to Moscow.

"We are watching closely," Jake Sullivan told ABC "This Week" co-anchor Martha Raddatz. "We know they haven't taken it off the table. And we are sending a clear message, as are our European allies, that this would be a real mistake because those weapons would be used to bombard cities and kill civilians, and China should want no part of that."

Sullivan said it was difficult to say whether China is "backing on, backing off" of the decision but that "what I can say is so far, we have not seen them do it."

Chinese officials have defended their relationship with Russia as "built on the basis of non-alliance, non-confrontation and non-targeting of third countries."

But President Joe Biden told ABC's David Muir in an interview last week that the U.S. stood ready to respond if Beijing moved forward with sending weapons.

Biden has ruled out giving Ukraine F-16 fighter jets "for now," despite repeated requests from President Volodymyr Zelenskyy, Sullivan said on "This Week." He called it a "question for later."

Sullivan said that the U.S. government's focus right now is to help Ukrainians "retake territory on the ground" in its southern and eastern territories.

Asked if it's possible the U.S. provides F-16s in the future, Sullivan reiterated that that the White House has been prioritizing the immediate needs of this war and will continue to do so.

"Every phase of this war, the president has tried to make sure that the Ukrainian military gets what they need. In the first phase, as they were defending Kyiv, that was Javelin anti-tank weapons and Stinger anti-air systems. And that worked. It helped Ukraine defend Kyiv. In the second phase, it was heavy artillery to help them hold against the Russians pushing in eastern Ukraine. In this phase, the critical element is ground maneuver capability. And that means tanks, armored personnel carriers, infantry fighting vehicles," Sullivan said. "And so what the president is saying is he's focused on those capabilities."

Pressed further by Raddatz on the possibility the U.S. could eventually approve fighter jets -- a move endorsed not just by Zelenskyy but some leading lawmakers like House Foreign Affairs Committee Chair Michael McCaul -- Sullivan told her, "We will cross the bridge of future phases of this war when they come."

Secretary of State Antony Blinken told Raddatz a week ago, on "This Week," that one reason Biden is not supplying Ukraine with F-16s is because of the required training and maintenance.

"So why not teach them now? So if they need them, if you want to approve it in the future, they'll have them ready to go," Raddatz said to Sullivan.

"From our perspective, the most important thing that we can do is make sure that we maintain focus on what is the highest priority and honestly, Martha, the highest priority right now is to move as rapidly as possible to build up their capacity to de-occupy those portions of Ukraine that are still being occupied brutally and bloodily by Russian forces," he said. "We expect that that will be the central focus of the Ukrainians as well as of our support for the Ukrainians in the weeks and months ahead."

In January, Biden approved 31 Abrams tanks to be sent to Ukraine, but last week the Secretary of the Army Christine Wormuth said those vehicles may not even get to the country this year.

"How is that helpful if you don't approve them in time and get the speed to get things like that over there?" Raddatz asked on "This Week."

Sullivan defended the decision, saying the release of Abrams tanks was done in coordination with Germany as a precondition so they would send German-made Leopard tanks to the battlefield, which will arrive much more quickly.

He said this was "an example of Joe Biden rallying the global coalition to get Ukraine what it needs."

"The president said, 'OK, I'm going to be the leader of the free world, I will send Abrams down the road if you send Leopards now.'"

Separately, following the shoot-down of a suspected Chinese spy balloon over U.S. airspace and three unidentified flying objects over North America, there have been no other instances of the military downing any possible threats.

Raddatz asked if this was because radar has been recalculated once again, but Sullivan said the NORAD Commander "has not recalibrated our radar."

"We continue to be vigilant for unidentified objects coming into U.S. territory," he said. "What we did do at President Biden's direction, Martha, is put in place a set of policy parameters for when we would take lethal action against an object, to shoot it down, as opposed to deal with it in other ways."

A "leading explanation" for the three additional objects is that they were commercial or civilian balloons, government officials have said.