Hollywood actor Michael Douglas, a UN "messenger for peace," wants President Barack Obama to issue a strong message against nuclear weapons when he visits Hiroshima in Japan later this month.Douglas told reporters at the United Nations in Geneva, where nuclear negotiations have been stuck for 20 years, that the nuclear danger was greater than during the Cold War, largely due to a "huge escalation" in US-Russia tensions and increasing recklessness in their close-quarter contacts."There's this kind of crazy tension between US and Russia. We have our issues but I don't quite see that all of this posturing is helping anybody," he said."The number of weapons that are on trigger alert is frightening. So the time for somebody to possibly make a mistake and correct it is very very short."Douglas said he "found religion" in the anti-nuclear cause after the Three Mile Island nuclear accident in 1979, within days of the opening of his film The China Syndrome, which dealt with an emergency at a nuclear plant.Standing beside Joseph Cirincione, president of Ploughshares Fund, a global security organization, Douglas recalled Obama's 2009 speech in Prague, where the president promised concrete steps towards a nuclear-free world."I think we could say he's been a disappointment because there's not been follow through, and I do hope now for his legacy as he begins to leave office, that he's going to have something strong to say at Hiroshima."Cirincione said Obama had made good early progress on nuclear non-proliferation, but had made only modest cuts in arsenals and was leaving $1 trillion in new nuclear contracts in the pipeline for his successor."Every single weapon in the nuclear arsenal is now due for replacement or an upgrade. It's a looming disaster," he said.Douglas, 71, said he was also a friend of Donald Trump, but he was not confident the United States would make any advances in nuclear disarmament if Trump won the presidency."I guess one of his strengths, or weaknesses depending how you look at it, is his unpredictability," he said.