US President Donald Trump has reaffirmed the one-China policy in his first phone call with China’s President Xi Jinping after taking office. In the Friday morning call that was not announced beforehand, Trump told Xi that he fully respected the importance of the one-China policy and that his administration would adhere to it, the state-run China Central Television reported. Trump made the pledge at Xi’s request, according to the White House. “The two leaders discussed numerous topics and President Trump agreed, at the request of President Xi, to honour our one-China policy,” the White House said in a statement. The one-China policy, which recognises that Taiwan is part of China, has been seen as the basis of Sino-US relations since the 1970s. Donald Trump sends letter to Xi Jinping seeking ‘constructive relationship’ with China Friday morning’s call was the first between the two leaders since Trump was sworn in as US president in late January. The call marked a major shift in Sino-US relations, which entered into a period of greater uncertainty after Trump took office. Xi was quoted by state television as saying he appreciated Trump’s reiteration of the one-China policy and hoped to work with his US counterpart to promote the steady development of bilateral ties. Both leaders also agreed to keep close communications, state television reported. The White House described the call as "extremely cordial” and the two leaders also extended invitations to meet in their respective countries. Watch: China commends Trump for his letter to President Xi Jinping What is the one-China policy and how did it become the bedrock of Sino-US ties? Relations between Beijing and Washington have been markedly strained since Trump’s phone call with Taiwanese President Tsai Ing-wen in December after his election victory. The Trump-Tsai call was the first between a US president or president-elect and a Taiwanese leader since Beijing and Washington established diplomatic relations in 1979. Beijing has been irked by Trump’s previous remarks on cross-strait ties and has said bilateral relations would be damaged if the US refused to reaffirm the one-China policy. Analysts believe the Trump-Xi call, which took place on the eve of Japanese Prime Minister Shinzo Abe’s official visit to the White House, was also aimed at easing tensions with Beijing and minimising a potential fallout from Abe’s second face-to-face meeting with Trump.