(Bloomberg) -- U.S. President Joe Biden reminded Chinese President Xi Jinping that he voted as a senator to support Taiwan’s self-defense when the two discussed the island in a virtual summit Monday, National Security Adviser Jake Sullivan said. 

“The two leaders spent a good amount of time on the question of Taiwan,” Sullivan said at a Brookings Institution event on Tuesday. “He also reminded President Xi that he voted for the Taiwan Relations Act as a senator.”

The 1979 law guides U.S. relations with Taiwan, establishing that the U.S. will support its self-defense with weapons sales and discourage any attempt by China to retake the island by force.

Sullivan was one of the few officials who participated in the summit, which lasted three and a half hours. U.S. officials said the discussion was candid and respectful.

As anticipated, the conversation between Biden and Xi was mostly aimed at setting the rules of engagement between the world’s two largest economies, in an effort to avoid unintended military conflict or economic damage. China and the U.S. have been at odds over Taiwan, the South China Sea, trade and human rights, among other issues.

The leaders also discussed how the their countries “can work together to ensure global energy supply and price volatility do not imperil the global economic recovery,” Sullivan said. “The two presidents tasked their teams to coordinate on this issue expeditiously.”

Biden Charts Path Forward With Xi Even as Taiwan Tensions Simmer

Biden said in a CNN town hall last month that the U.S. would defend Taiwan if the island’s status quo was changed unilaterally, a statement the White House later clarified was only reiterating longstanding U.S. policy. For decades, the U.S. has practiced what’s known as “strategic ambiguity,” declining to explicitly promise to defend Taiwan in the event of a Chinese attack but also holding out the possibility that it might.

Chinese readouts of the leaders’ meeting said Biden was opposed to Taiwan’s independence and said Xi warned that those playing with fire around Taiwan “would inevitably burn themselves.”

Taiwan’s foreign ministry accused Beijing of “purposely” mischaracterizing Biden’s statements.

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