President Biden described the implications for Beijing if it decides to provide assistance to Russia's invasion of Ukraine in a nearly two-hour phone call with Chinese leader Xi Jinping, a senior White House official told reporters.

The official called the conversation "direct," "substantive," "detailed" and "candid," but would not describe what those implications were.

"I'm not going to publicly lay out our options from here," the official said. "This was really about President Biden being able to lay out very clearly in substantial detail with a lot of facts ... walking President Xi through the situation."

The official declined to describe President Xi's reaction to the discussion.

The call largely focused on Russia's invasion of Ukraine and the implications for the U.S.-China relationship and international order, the official said.

Biden reportedly shared a detailed review of how things have developed and underscored his support for diplomatic resolution while emphasizing U.S. concerns about Russian disinformation about biological weapons and concerns about echoing that disinformation.

Asked whether Biden asked Xi to intercede with Putin, the official said that "the president wasn't really making specific requests of China."

"Our view is that China will make its own decisions," the official said.

While the call focused on Russia and Ukraine, Xi raised Taiwan, the official said. Biden restated the longstanding U.S. position on the self-governed territory, which China claims.

The official said that the leaders assigned their teams to follow up on the conversation in days and weeks ahead.

U.S. national security adviser Jake Sullivan had sent a similar message on Monday during a meeting with top Chinese diplomat Yang Jiechi in Rome, a senior administration official told reporters.

The official declined comment on whether the U.S. has information that China is providing or is open to providing Moscow with financial and military assistance but did say Sullivan spoke directly about concerns and the "potential implications and consequences of certain actions."

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