"This is not entertainment, this is not a reality show. This is a contest for the presidency of the US," Obama said.
"With respect to the Republican process and Mr Trump, there's going to be plenty of time to talk about his positions on various issues. He has a long record that needs to be examined. And I think it's important for us to take seriously the statements he's made in the past," Obama told reporters.
Trump has provoked number of protests with his controversial speeches and proposals ranging from banning Muslims from entering the US to building a wall to keep out Mexican migrants to slashing US funding for NATO.
"I think I just want to emphasise the degree to which we are in serious times and this is a really serious job," Obama said and added that every candidate, every nominee needs to be subject to exacting standards and genuine scrutiny.
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"It means that you've got to make sure that their budgets add up. It means that if they say they've got an answer to a problem that it is actually plausible and that they have details for how it would work, and if it's completely implausible and would not work, that needs to be reported on and the American people need to know that," he said.
"But what I'm concerned about is the degree to which reporting and information starts emphasising the spectacle and the circus. Because - that's not something we can afford."
During the news conference, Obama also took a dig at the Republican leadership that has resulted in the rise of Trump.
"There is no doubt that there is a debate that's taking place inside the Republican Party about who they are and what they represent. Their standard bearer at the moment is Donald Trump," he said.