Hillary Clinton formally concluded the US Democratic presidential race last night with a win in the District of Columbia primary.
She then turned her focus to uniting the party during a 90-minute private meeting with defeated rival Bernie Sanders.
Mrs Clinton secured enough delegates to clinch the nomination last week.
She met Mr Sanders in a downtown Washington hotel yesterday as the sometimes bitter primary combatants searched for common ground ahead of the 8 November election against presumptive Republican nominee Donald Trump.
Mr Sanders has resisted pressure to bow out and endorse Mrs Clinton in a show of party unity, choosing to continue his campaign as leverage to win concessions from Mrs Clinton on his policy agenda and reforms to the Democratic Party nominating process.
Both camps described the meeting as "positive" and said the two noted their shared commitment to stopping Mr Trump and pursuing issues such as raising the minimum wage, eliminating undisclosed money in politics, making college affordable and making healthcare coverage more accessible.
Sanders spokesman Michael Briggs said the meeting was "a positive discussion about how best to bring more people into the political process and about the dangerous threat that Donald Trump poses to our nation".
Also attending were Mr Sanders' wife Jane, Clinton campaign chairman John Podesta and the two campaign managers, Jeff Weaver for Mr Sanders and Robby Mook for Mrs Clinton.
Mr Sanders had promised to stay in the Democratic race until the final vote was cast in the Washington, DC, primary, although in the past week he has stopped talking about capturing the party's nomination and instead focused on ways to advance his policy goals.
He scheduled a national video address to supporters tomorrow night, telling them in an email message that "the political revolution continues",
At a news conference before the Washington meeting, Mr Sanders said he would also demand changes to make the Democratic nominating process more equitable, including replacing the Democratic National Committee leadership, letting independents take part in the voting and eliminating superdelegates, who are unelected and are free to support any candidate.
"The time is long overdue for a fundamental transformation of the Democratic Party," Mr Sanders said.
Mrs Clinton easily beat Mr Sanders in the District of Columbia, winning 79% to his 21% in a primary that closed the more than four-month, state-by-state battle for the Democratic nomination that began on 1 February in Iowa.
During a visit to Capitol Hill earlier yesterday, Mr Sanders told Democratic senators he would take his message of progressive values and party reform to the convention.
"I'm open to that, I think we should all be open to that," Senator Dick Durbin of Illinois told reporters afterward.
"It's not a surprise that the American people are sceptical of all of us in political life. And we ought to step back and reassess why, and what we can do about it."
Top Democrats have taken steps in the last week to begin rallying behind Mrs Clinton and ease Sanders out of the race without alienating his supporters.
President Barack Obama endorsed Mrs Clinton last Thursday, hours after meeting Mr Sanders at the White House.
Mrs Clinton also secured the endorsement of Senator Elizabeth Warren of Massachusetts, a leader of the party's progressive wing.
Mrs Clinton has already turned her attention on the campaign trail to the race with Mr Trump, rejecting the New York businessman's renewed calls for a ban of the entry of foreign-born Muslims into the United States after the mass shooting at a gay club in Orlando, Florida, by an American man who claimed allegiance to the so-called Islamic State.
"I have clearly said that we faced terrorist enemies who use a perverted version of Islam to justify slaughtering innocent people. We have to stop them, and we will," Mrs Clinton said in Pittsburgh, Pennsylvania.
"But I will not demonise and declare war on an entire religion."
