The US Electoral College has certified Donald Trump as president, despite a last-ditch effort to deny him the White House.

Video shows the moment electors in Texas announced President-elect Donald J. Trump has surpassed 270 Electoral College votes, meaning that he has the required number of votes to be elected president.

Six weeks after winning the polls, the Republican has secured the 270 votes needed to formalise his victory. Reacting to his win, Mr Trump promised to “work hard to unite our country and be the president of all Americans”.