US President Donald Trump said on Monday that the Democrats' decision to interview his longtime fixer, lawyer Michael Cohen, on the same day as a meeting with Kim Jong Un may have led to the North Korea summit ending with no deal."For the Democrats to interview in open hearings a convicted liar & fraudster, at the same time as the very important Nuclear Summit with North Korea, is perhaps a new low in American politics and may have contributed to the 'walk.'" Trump said on Twitter, referring to his decision to walk away from what he previously said was a bad deal with Kim."Never done when a president is overseas. Shame!"Last week in Hanoi Trump and Kim met for the second time to try to negotiate a deal that would surrender some of North Korea's nuclear weapons arsenal in return for sanctions relief.