Presumptive Democratic presidential nominee Hillary Clinton has received an endorsement from her former rival Bernie Sanders.
The Vermont senator and former Democratic presidential candidate is appearing with Mrs Clinton at a campaign event in New Hampshire.
Mrs Clinton and Mr Sanders have been negotiating since she all but guaranteed the nomination in June.
Mr Sanders hopes to have a large influence the Democratic platform.
“She will be the Democratic nominee for president and I intend to do everything I can to make certain she will be the next president of the United States,” he said.
“This campaign is about the needs of the American people and addressing the very serious crises that we face. And there is no doubt in my mind that, as we head into November, Hillary Clinton is far and away the best candidate to do that.”
He defeated Mrs Clinton in New Hampshire’s primary contest in February.
“Thank you for your lifetime of fighting injustice,” said Mrs Clinton, and credited Mr Sanders for bringing new Americans into the political process. “I’m proud to be fighting behind you… it’s a time for all of us to stand together.”
She spoke on student debt, Wall Street, raising the minimum wage, the US tax code, reforming policing, strengthening the middle class, climate change, health care and reducing gun violence.
His supporters have largely decided to support Mrs Clinton in an effort to stop presumptive Republican nominee Donald Trump from winning the White House.
Mr Sanders stayed in the Democratic race far longer than many expected, for weeks after it became clear he would not secure the delegates needed to win the nomination.
He has pressed Mrs Clinton to support his views on higher education, health care and the minimum wage.
“It is no secret that Hillary Clinton and I disagree on a number of issues. That’s what this campaign has been about. That’s what democracy is about,” said Mr Sanders.
“But I am happy to tell you that… there was a significant coming together between the two campaigns and we produced, by far, the most progressive platform in the history of the Democratic Party.”
Mr Trump, who has been trying to court Sanders supporters, wrote in a tweet that Mr Sanders has “totally sold out to Crooked Hillary Clinton. Fans are angry!”
“The candidate who ran against special interests is endorsing the candidate who embodies special interests,” his campaign said in a release.