President Donald Trump asked Chinese President Xi Jinping whether China wanted to purchase American weapons, according to David Perdue, Trump’s ambassador to China. The extraordinary proposal emerged as Trump defended a pending U.S. arms sale to Taiwan.

Perdue said Trump portrayed the planned Taiwan sale as one of many weapons transactions Washington conducts around the world. Trump then apparently decided to extend the sales pitch directly to the leader of China, an ascendant geopolitical rival.

If completed, such a sale would upend generations of American policy toward China and Taiwan. It could also expose U.S. technology to a potential foe, adding significant consequences to an offer that Perdue described without saying when Trump made it.

Perdue disclosed the conversation while speaking with Shannon Bream on “Fox News Sunday.” His appearance came days after Trump hosted Xi for a state visit in Washington, where the two leaders held private talks at the White House.

Bream raised concerns expressed by Republican and Democratic lawmakers about delayed aid packages and weapons orders for Taiwan. The self governing democracy relies on weapons to defend itself against China’s threat to invade the island.

She asked whether the United States was denying arms to Taiwan as a way to appease Xi, who visited Trump last week. Perdue rejected that suggestion and defended the president’s record on weapons sales to Taiwan.

Perdue said Trump “is as strong on Taiwan as I’ve ever seen anybody” and argued that the president has sold the island plenty of weapons. He also said Trump and Xi continue discussing future U.S. weapons sales to Taiwan.

“But President Trump continues to say, ‘Hey, we sell arms to other people around the world,’” Perdue said. “He actually asked President Xi, would he like to buy some, at one point.”

The United States is required by its own laws to provide Taiwan with the means to defend itself. Washington does not recognize Taiwan as a country, but remains the island’s strongest informal supporter and its provider of arms.

Multiple American leaders have kept one central question deliberately ambiguous. They have not made clear whether the United States would commit military forces to defend Taiwan, described in the source as a U.S. ally, if China launched an invasion.

China has repeatedly pressed Washington to stop selling weapons to Taiwan. That demand featured prominently during an earlier summit in May between Trump and Xi in Beijing, where arms sales again became part of the relationship between the two governments.

Following that May meeting, the United States paused the sale of a record $14 billion weapons package. Trump also described arms sales to Taiwan as a “very good negotiating chip” in dealings with China.

During the private White House discussions last week, Xi urged Trump to oppose Taiwanese independence, according to Chinese state media. The appeal came as questions continued over delayed weapons orders and Washington’s commitments to the island.

China’s foreign ministry did not confirm Perdue’s account when spokesperson Guo Jiakun was questioned about it Monday in Beijing. Guo instead told reporters that China has always strengthened its national defense capabilities according to its needs.

Guo also said China remains committed to maintaining world peace and stability. His response left Perdue’s description of Trump’s unlikely sales offer neither confirmed nor directly rebutted by the Chinese government.

Perdue’s account places Trump’s pitch to Xi alongside the administration’s ongoing conversations about future weapons sales to Taiwan. It also follows the pause of the $14 billion package and Trump’s characterization of Taiwan arms sales as leverage in negotiations with China.