Trump signs China trade pact and boasts of 'the biggest deal ever seen'

President signs first phase of new agreement with China, hours after Democrats named team that will prosecute him in Senate

Donald Trump has signed the first phase of a new trade agreement with China after two years of tension between the two superpowers that have rattled economies around the world.

Related: Trump vaunts his China trade pact - but some say it's too little, too late