Chinese leader Xi Jinping pleaded with President Joe Biden to prevent Speaker Nancy Pelosi from making her controversial visit to Taiwan, according to a new report.

Xi made the request when the two leaders spoke on a July 28 phone call, but Biden responded by informing him that Congress is a separate branch of government and not under his control, a senior White House official told the Washington Post.

The conversation came as Beijing issued unhinged threats ahead of Pelosi's early August visit to Taiwan, a self-governed island that China considers to be part of its sovereign territory. 

During the call, Biden warned Xi against taking any provocative or coercive steps in response to Pelosi's visit to the island, according to the official. 

The White House did not immediately respond to a request for comment from DailyMail.com on Saturday morning.

The official White House readout of Biden's July 28 call with Xi does not mention discussion of Pelosi's then-pending Taiwan visit.

'On Taiwan, President Biden underscored that the United States policy has not changed and that the United States strongly opposes unilateral efforts to change the status quo or undermine peace and stability across the Taiwan Strait,' the readout says. 

Publicly, Biden expressed disapproval of Pelosi's Taiwan visit, although the White House's messaging on the subject was at times tepid and muddled.

'The military thinks it's not a good idea right now,' Biden said in July when asked about Pelosi's plans. 'But I don't know what the status of it is.' 

Privately, Biden administration officials were said to be frustrated by Pelosi's trip, viewing it as needlessly aggravating tensions with China in a move largely designed to burnish her legacy as what is likely her final term as speaker winds down. 

However, though Biden is the leader of the Democratic Party and head of the executive branch of government, he does not have authority over members of Congress, even the top House Democrat, Pelosi.