US President Barack Obama has asked Donald Trump to take the presidential election seriously and not treat it "like a reality show", insisting that Trump "has a long record that needs to be examined". When asked about Trump's candidacy at a media briefing in the White House, Obama did not point to any specific issue, but told reporters: "I think I just want to emphasise the degree to which we are in serious times and this is a really serious job. This is not entertainment. This is not a reality show. This is a contest for the presidency of the United States."

This is the first time Obama has made a public comment about Trump after the latter has established his position firmly as the presumptive GOP nominee following the dropping out of two rivals from the presidential race.

The outgoing president suggested that attention must be paid to campaign promises made by each candidate, especially on issues like budget, economy and foreign policy, the New York Times reported.

"You know, if they take a position on international issues that could threaten war or has the potential of upending our critical relationships with other countries or would potentially break the financial system that needs to be reported on."

Referring to the media coverage of the campaign, Obama said: "One thing that I'm going to really be looking for over the next six months is that the American people are effectively informed about where candidates stand on the issues, what they believe, making sure that their numbers add up, making sure that their policies have been vetted and that candidates are held to what they've said in the past."

Top Trumpisms: Donald Trump's worst gaffes, blunders and unpresidential remarksIBTimes UK

Chaos within the party

There has been a lot of confusion within the Republican party, with some its members still sceptical and undecided on supporting Trump, while some have lauded him.

Former Republican nominee Bob Dole, who lost to Bill Clinton in the 1996 elections, announced that he would back Trump. "The voters of our country have turned out in record numbers to support Mr Trump. It is important that their votes be honoured and it is time that we support the party's presumptive nominee," NBC quoted him as saying.

However, former governor Jeb Bush, who did not win the nomination from Florida, posted on his Facebook page that he will not vote for Trump. US House Speaker Paul Ryan is also among those who had said that they would not endorse the real estate mogul from New York.