"I look forward to meeting with her in the near future to see how we can work together to defeat Donald Trump," Sanders said after the meeting.
While he vowed to compete in next week's primary, he promised to carry only his platform to his party's convention this summer.
"These are some of the issues that many millions of Americans have supported during my campaign,” Sanders said. “These are the issues that we'll take to the Democratic National Convention in Philadelphia at the end of July."
Sanders thanked Obama and Vice President Joe Biden for not putting their “thumb on the scales” during the Democratic primaries. The senator offered no review of his 1-1/2-hour meeting with the president.
Obama told attendees at a fundraiser in New York on Wednesday night, “We just ended or sort of ended our primary season.” Top Democratic supporters of Sanders have similarly told ABC News of their readiness to rally behind Clinton.
But White House officials have maintained that Obama still has not officially endorsed Clinton, although they say that is imminent.
After the meeting, Sanders went to Capitol Hill to hold meetings with other top Democrats, including Senate Minority Leader Harry Reid of Nevada and Sen. Chuck Schumer of New York. He will then meet privately with Biden at the Naval Observatory in Washington.