US Senator Bernie Sanders has said he will vote for his Democratic rival Hillary Clinton in November’s presidential election.
The two have fought for the Democratic nomination, which former Secretary of State Mrs Clinton won this month.
Mr Sanders, a self-described socialist, told MSNBC he would do everything in his power to defeat the likely Republican nominee, Donald Trump.
But he stopped short of saying he would end his campaign.
He said his job now was to “fight for the strongest possible platform” at the party’s convention in July, including a higher minimum wage.
But Sanders dismissed the idea that he should withdraw from the race.
“Why would I want to do that when I want to fight to make sure that we have the best platform that we possibly can, that we win the most delegates that we can”, the Vermont senator said.
Taking the plunge: Anthony Zurcher, BBC North America
Like a swimmer getting into a too-cold pool, Bernie Sanders’ acceptance of Hillary Clinton as the Democratic nominee has come reluctantly and not without a few shivers.
First he admitted it was unlikely that he would be the nominee. Now he has said he will vote for her over Donald Trump in the autumn general election.
Given that he has not yet officially ended his campaign, the full endorsement plunge is still to come – but perhaps he will find the water not as uninviting as he feared.
The Vermont senator certainly picked a not-so-slow news day to offer this latest revelation.
With the British referendum dominating the world’s headlines and American pundits and politicians wondering what this means for the mood of their own electorate, the Sanders announcement will be well below the fold of most newspapers.
Maybe, however, the overnight news – accompanied by a recent poll showing almost half of Sanders backers wouldn’t support Mrs Clinton in the general election – have convinced the senator that the stakes are too high to leave his presidential preferences in doubt.
Although Mrs Clinton has won enough of the all-important delegates to secure the nomination, she will not be declared the official nominee until July’s convention.
Mr Sanders has failed to give the former first lady a full endorsement.
Last week Mr Sanders vowed to work with Mrs Clinton to prevent Mr Trump from winning the White House and promised to continue his fight to “transform” the Democratic party.
When asked if his decision to remain in the race hindered Clinton’s chances in the general election, Sanders said, “You talk about disunity, I talk about people in the political process and wanting to have a government and party that represents all of us.”
“What we want is a government that represents all of us,” he added. “And that’s what I intend to fight for.”