Delivery workers use their mobile phones in Beijing. Trump first inflamed tensions with Chinese President Xi Jinping by accepting a congratulatory phone call from Taiwan in November | Fred Dufour/AFP via Getty Images Trump pledges to honor ‘one China’ policy in call with Xi Trump inflamed tensions with China by accepting a congratulatory phone call from Taiwan in November.

President Donald Trump backed down from a blustery threat in an effort to ease tensions with China during his first phone call with the country's president on Thursday night.

Trump, who first inflamed tensions with Chinese President Xi Jinping by accepting a congratulatory phone call from Taiwan in November, said just two months ago that he might not honor the country's "one China" policy, under which the U.S. recognizes China's designation of Taiwan as a Chinese state, unless he won concessions on trade in return.

According to a White House readout of Thursday's "lengthy" phone call, "President Trump agreed, at the request of President Xi, to honor our "one China" policy.

"Representatives of the United States and China will engage in discussions and negotiations on various issues of mutual interest," the statement continued. "The phone call between President Trump and President Xi was extremely cordial, and both leaders extended best wishes to the people of each other's countries."

Trump, whose initial diplomatic phone calls with some world leaders have been marred by misunderstandings and unusual bellicosity even with longstanding allies, hadn't spoken with Xi until Thursday evening. According to a New York Times report, Trump had sent Xi a letter earlier this week wishing him a happy Chinese New Year, an apparent effort to thaw a relationship that had been frozen since the November election.

Trump and Xi also extended invitations to meet in their respective countries, according to the White House.

The new diplomatic efforts to improve what is arguably America's most important bilateral relationship — a surprise move from the former real-estate mogul who has telegraphed a foreign policy driven largely by a mercantilist approach to geopolitics and his own unpredictability — come after a campaign in which Trump labeled China as a currency manipulator, blamed it for stealing American jobs and vowed to enact tough new trade policies.