U.S. President Barack Obama on Monday said he was yet to hear a strong factual argument against a nuclear deal with Iran and criticized rhetoric about the agreement from some leading members of the Republican party.Obama, speaking in Ethiopia during a tour of African nations, said the majority of the world`s nuclear scientists and non-proliferation experts backed the July 14 accord, indicating it was the best way to stop Iran acquiring nuclear weapons."There is a reason why 99 percent of the world thinks it’s a good deal -- it’s because it’s a good deal," Obama said during a joint press conference with Ethiopian prime minister Hailemariam Desalegn in the capital Addis Ababa."The good news is that I’ve not yet heard a factual argument on other side that holds up to scrutiny," he added.Obama said rhetoric on the Iran deal from Mike Huckabee, who is bidding to be the Republican party`s candidate in the next presidential election, was part of a pattern of comments that were ridiculous and sad.Obama also criticized comments by Republican candidate Donald Trump about senator and 2008 Republican presidential nominee John McCain, a war veteran, saying presidential debates deserved better.