Washington, Jan 13 : The US State Department has said that a planned visit to Taiwan by its United Nations (UN) envoy was cancelled due to the upcoming presidential transition. Kelly Craft was scheduled to arrive in Taipei on Wednesday after Washington abruptly ended long-time curbs on contacts with Taiwan officials, the BBC reported. It led Beijing, which views democratic Taiwan as a breakaway province, to warn the US against "playing with fire". Taiwan expressed regret but also "respect" for the US decision. The planned visit by Craft, the US Ambassador to the UN, was only announced late last week and would have come days before the inauguration of President-elect Joe Biden. It was viewed by analysts as a last-minute bid by outgoing President Donald Trump's administration to seal its position on the thorny issue of Taiwan after a year of escalating Sino-American tensions. US Secretary of State Mike Pompeo said on Tuesday that all travel this week had been cancelled - including his own trip to Europe - as part of the transition to the incoming Biden administration. Biden is set to take office on January 20. Taiwan's government expressed its regret at Ambassador Craft's cancelled trip, while also conveying "understanding and respect for the decision", it said in a statement. Bitter exchanges over self-governing Taiwan, a firm US ally, have emerged over the last year as Washington's relationship with Beijing has spiralled to a new low. Under President Trump, the US has established much closer ties with Taipei - ramping up arms sales and sending senior officials to the territory, despite fierce warnings from China. Over the weekend Pompeo said the US would end the "self-imposed restrictions" on its interactions with Taiwan officials that were introduced decades ago to "appease" the mainland Chinese government. The move was seen as a key shift in diplomatic relations between the two places in the final days of Trump's presidency. China was furious, saying "any actions which harm China's core interests will be met with a firm counter-attack and will not succeed". Tensions between China and Taiwan have intensified in recent years and Beijing has not ruled out the use of force to take the island back. Like most nations, the US has no official diplomatic ties with Taipei, but it is bound by law to provide the island with the means to defend itself. /IANS