WASHINGTON: US President Barack Obama has urged American people to make a 'sensible' choice when they pick his successor, saying the job is harder than 'hosting a talk show or a reality show'

 He said that he believed Donald Trump would not become president and warned the American public to consider that his successor would have access to the nuclear codes, The Telegraph reported.

 Speaking at a press conference in California after hosting a summit with Southeast Asian leaders on Tuesday, Obama launched a scathing attack on the front-runner for the Republican presidential nomination in which he identified Mr Trump by name.

 He said: "I continue to believe Mr Trump will not be president. And the reason is I have a lot of faith in the American people. I think they recognise being president is a serious job. It's not hosting a talk show or a reality show, it's not promotion, it's not marketing, it's hard and a lot of people count on us getting it right.”

 "It's not a matter of pandering and getting in the news every day. It requires being able to work with leaders around the world in a way that reflects the importance of the office, and gives people confidence that you know the facts, and you know their names, and you know where they are on a map, and you know something about their history."

 Obama added: "The guy who's standing where I stand has the nuclear codes with him. He can order 21-year-olds into fire.”

 "This is reported as entertainment but as you get closer (to the election) the reality has a way of intruding. The American people are pretty sensible and I think they'll make a sensible choice."

 He also attacked the Republican Party saying foreign observers were "troubled" by the rhetoric of its candidates.

 He said: "This is not just Mr. Trump. Everyone's focusing on Trump because he says it in a more interesting way. He may up the ante in anti-Muslim sentiment, but if you look at what the other Republican candidates have said, that's pretty troubling, too. They're all denying climate change and that's troubling to the scientific community."

 Mr Obama also singled out Marco Rubio, the Florida senator and Republican presidential candidate, although he did not name him.

 He referred to a law Mr Rubio had proposed to solve the immigration crisis, which the president himself had supported.

 Mr Obama said: "Now he's running away from it as fast as he can."

The president refused to make a choice between the two Democratic candidates Hillary Clinton and Bernie Sanders.