Chinese President Xi Jinping on Thursday warned US President Joe Biden against "playing with fire" over Taiwan, as Beijing's concerns mounted over a possible visit to the Chinese-claimed island by US House Speaker Nancy Pelosi. Chinese state media said Xi told Biden in their fifth call as leaders that the United States should abide by the "one-China principle" and stressed that China firmly opposed Taiwanese independence and interference of external forces. Beijing has issued escalating warnings about repercussions should Pelosi visit Taiwan, which says it is facing increasing Chinese military and economic threats. A visit by the House speaker would be a dramatic, though not unprecedented, show of US support for the island. "Those who play with fire will only get burnt," Chinese state media quote Xi as telling Biden. "(We) hope the US side can see this clearly." China has given few clues to specific responses it might make if Pelosi, a long time critic of Beijing, particularly on human rights issues, makes the trip. The presidents' call lasted over two hours. US officials had said it would have a broad agenda, including discussion of Russia's war in Ukraine. At its core though, US officials said they saw the exchange as another chance to manage competition between the world's two largest economies, whose ties have been increasingly clouded by tensions over democratically governed Taiwan, which Xi has vowed to reunite with the mainland, by force if necessary. Washington does not have official relations with Taiwan and follows a "one-China policy" that recognizes Beijing, not Taipei, diplomatically. But it is obliged by US law to provide the island with the means to defend itself, and pressure has been mounting in Congress for more explicit support. "This is about keeping the lines of communication open with the president of China, one of the most consequential bilateral relationships that we have, not just in that region, but around the world, because it touches so much," White House national security spokesman John Kirby told reporters ahead of the call. One person briefed on planning for the call said the Biden administration thinks leader-to-leader engagement is the best way to lower tensions over Taiwan. — Agencies