The 56-minute speech was a rebuke to the world body and a return to form for Trump, who routinely bashed the UN during his first term as president. Trump offered his US immigration crackdown as a case study for what other world leaders should do to curb mass migration that he says is altering the fabric of nations. But in Tuesday’s speech, Trump mocked NATO allies for not shutting down purchases of Russian oil and said he would impose strong economic measures against Moscow. Trump, who has cast himself as a peacemaker in a bid to win the Nobel Peace Prize, complained that the United Nations did not support his efforts to end conflicts around the world. “These are the two things I got from the United Nations - a bad escalator and a bad teleprompter,” Trump said,noting that Melania Trump nearly fell when the escalator stopped abruptly.