US President Donald Trump has said, on Thursday, that he will leave the White House if the Electoral College formalises President-Elect Joe Biden’s victory — even as he insisted such a decision would be a “mistake.”

According to numbers from the polls, Biden won the presidential election with 306 electoral college votes––many more than the 270 required––to Trump’s 232. Biden also leads Trump by more than 6 million votes in the popular vote tally. Despite this, Trump has, so far, defied tradition by refusing to concede defeat, instead, making a series of claims about alleged ballot fraud and launching legal attempts to challenge the outcomes in several states such as Pennsylvania and Michigan. However, desperate efforts by Trump and his aides to overturn results in key states, either by lawsuits or by pressuring state legislators, have failed.

Speaking to reporters during the US holiday, Thanksgiving, Trump said if Biden––who is due to be sworn in on 20 January––was certified the election winner by the Electoral College, he would depart the White House. Asked if he would leave the White House if the college vote went against him, Trump said: “Certainly I will. And you know that,” adding that: “If they do, they’ve made a mistake.”

However, Trump said: “It’s going to be a very hard thing to concede because we know there was massive fraud,” and declined to speak on whether he would attend Biden’s inauguration, which is due to take place on 20 January.

This is the first time the US President has taken questions from reporters since Election Day and, at times, he turned combative, calling one reporter a “lightweight” and telling him “don’t talk to me like that.” Trump’s administration has already given the green light for a formal transition to get underway.