“I want to congratulate Hillary Clinton as the presumptive Democratic nominee for president of United States. I know how hard this job can be, that’s why I think Hillary will be so good at it,” Mr Obama said in a videotaped statement.
“I’m with her. I’m fired up. And I can’t wait to get out there and campaign for Hillary,” Mr Obama said, praising her experience, judgment and values. “I don’t think there’s ever been someone so qualified to hold this office.”
The New York Post reports that moments later, Ms Clinton tweeted, “Honoured to have you with me, @POTUS. I’m fired up and ready to go! -H.”
Earlier, Sen. Sanders had vowed to carry on his progressive campaign at least through Tuesday’s primary in Washington DC.
“We will continue doing everything that we can to oppose the drift which currently exists [toward] a form of society whe-re a handful of billionaires exercise enormous power over our political, economic and media life,” Sen. Sanders said, sounding off on his usual themes of income inequality, crumbling infrastructure and the need for a crackdown on Wall Street abuses.
“These are the issues that we will take to the Democratic National Convention in Philadelphia at the end of July.”
He said he would meet soon with Ms Clinton to determine how the pair “can work together” to defeat Donald Trump, but took no questions.
The Vermont senator said he would campaign hard in DC, and called for the district to be granted statehood. He also said he was waiting for a final vote count in California, which he predicted would be closer than the current tally showing Clinton won the state by 13 points.
Both those positions indicated Sanders isn’t close to tossing in the towel.
But there was one point Sanders had common ground with Clinton.
“Donald Trump would clearly, to my mind and I think the majority of Americans, be a disaster as president of the United States,” he said, adding that the former reality TV star has insulted Mexicans, Muslims, African-Americans and women.
President Barack Obama walks with Democratic presidential candidate Sen. Bernie Sanders. Picture: APSource:AP
“I spoke briefly to secretary Clinton on Tuesday night and I congratulated her on her very strong campaign. I look forward to meeting with her in the near future to see how we can work together to defeat Donald Trump.”
Mr Obama and Sen Sanders smiled and spoke as they strolled into the White House and proceeded to the oval office for their meeting.
But he praised both Mr Obama and Vice President Joe Biden for showing “impartiality” during the course of the Democratic campaign.
Democratic presidential candidate Bernie Sandersspeaks to reporters outside the White House after a meeting with Barack Obama. Picture: APSource:AP
“They said in the beginning is that they would not put their thumb on the scales and they kept their word and I appreciate that very, very much,” Sen. Sanders said, before Mr Obama’s endorsement.
The senator has been under mounting pressure f-rom top Democrats to abandon his now-quixotic campaign, which became more than a longshot after Ms Clinton’s decisive performance in Tuesday’s primaries.
Sen. Harry Reid, the Democratic leader in the Senate, also huddled with the self-described socialist to explore how he might advance his leftist goals back in the Senate.
Democratic presidential candidate Sen. Bernie Sanders meets with Senate Minority Leader Harry Reid. Picture: APSource:AP
Sen. Sanders won contests in 22 states and got more than 12 million primary votes.
Ms Clinton stressed the importance of party unity as she prepared for what promises to be a brutal campaign between now and November.
“I think it’s time that we move forward and unite the party and determine how we are going to defeat Donald Trump, which is our highest and most pressing challenge right now,” she said Wednesday.
Sanders’ Democratic colleagues have been growing increasingly outspoken in nudging him to wind down his campaign and throw his support behind Ms Clinton.
But most stopped short of calling on him to d-rop out immediately.
Sen. Sanders had promised to continue his campaign to the last primary on Tuesday in Washington, DC.
Bernie Sanders and Hillary Clinton. Picture: SplashSource:Supplied
Even Sen. Jeff Merkley of Oregon, the one Senate Democrat to endorse Sen. Sanders, said it was time to get behind the former first lady.
“We have a nominee, that nominee is Hillary Clinton, congratulations to her for winning the Democratic primary,” Sen. Merkley said. “I think he’s laying the groundwork to make sure that we have a unified party at the convention and go into the November battle shoulder to shoulder.”
Though the White House has signalled for days that a presidential endorsement is imminent, Mr Obama has sought to give Sanders the space to exit the race on his own terms.
One open question is whether voters who helped elect Mr Obama — young people, minorities and women — will show up for Ms Clinton.
Aides said Mr Obama planned to target young voters who backed him and formed the core of Sen. Sanders’ support when he eventually joins Clinton on the campaign trail.
Barack Obama (R) shakes hands with Hillary Clinton during their 2008 race for the White House. Picture: SuppliedSource:AP
Some Democratic leaders doubted whether Sanders could be swayed by either Mr Obama or Ms Clinton.
“People talk to Bernie. But Bernie marches to his own drum. And that’s true if Clinton talks to him or if Obama talks to him,” former Pennsylvania Governor and Clinton backer Ed Rendell told the website.
“The president deserves an A for effort, but I’m not sure he’s going to have much of an impact.”
Senator Sanders vowed to continue his presidential campaign into next week, but said he would meet rival Hillary Clinton soon to foster party unity.
After an hour-long meeting with Mr Obama at the White House, Sen. Sanders did not d-rop out of the race or endorse Clinton, but said he would meet the former secretary of state “to see how we can work together.”
Sen. Sanders also said he will do everything in his power to make sure Donald Trump does not become the next president of the United States.