The White House on Wednesday welcomed a phone call between Chinese President Xi Jinping and Ukraine President Volodomyr Zelensky but said it was too soon to tell whether it would lead to a peace deal between Russia and Ukraine.

"That's a good thing," White House national security spokesperson John Kirby said about the call. "Now, whether that's going to lead to some sort of meaningful peace movement, or plan, or proposal, I just don't think we know that right now."

Xi spoke by telephone on Wednesday with Zelensky for the first time since Russia's invasion of Ukraine last year. The call came after months of pressure from Kyiv for such talks.

Xi told Zelensky that China would send special representatives to Ukraine and hold talks with all parties seeking peace, Chinese state media reported.

"We have long said we want this war to end," Kirby said. "It could end immediately if Putin would leave. That doesn't appear to be in the offing.

"If there's going to be a negotiated peace, it's got to be when President Zelensky is ready for it," Kirby said, adding that the United States would welcome "any effort to arrive at a just peace as long as that peace could be ... sustainable, and could be credible."

Kirby said the United States did not have advanced knowledge of the call, and would not necessarily expect to.

"These are two sovereign leaders and we're glad to see that they did talk," Kirby said.