Hillary Clinton has declared herself the Democratic Party nominee for US president, embracing her role in history as the first woman to lead a major party in a race for the White House.
The former first lady, US senator and secretary of state celebrated her victory over Bernie Sanders in the nominating race at a raucous event with supporters in Brooklyn, New York.
In her speech, Mrs Clinton, 68, placed her achievement in the context of the long history of the women's rights movement.
"Thanks to you, we have reached a milestone," she said. "We all owe so much to who came before."
Mrs Clinton spoke shortly after beating Mr Sanders in New Jersey's nominating contest, expanding her lead in gathering the delegates needed to clinch the nomination - and setting up a general election campaign against presumptive Republican nominee Donald Trump.
New Jersey was one of six states holding contests on Tuesday (Wednesday NZT), including California, the big prize where Mrs Clinton was still at risk of an embarrassing loss to Mr Sanders.
With about one third of the votes counted in California, Mrs Clinton held a 20 percentage point lead over Mr Sanders, but news networks said the race was still too close to call.
In her speech, Mrs Clinton appealed to Mr Sanders' supporters to join her and said the Democratic Party had been bolstered by his campaign for eradicating income inequality, which has commanded huge crowds and galvanised younger voters.
She edged Mr Sanders out, especially among older voters, with a more pragmatic campaign focused on building on the policies of her fellow Democrat, President Barack Obama.
But Mr Sanders, 74, showed no interest in ending his upstart candidacy, telling cheering supporters in California that he would go on campaigning through next Tuesday's primary in the District of Columbia and carry his political crusade - although not necessarily his campaign - to the convention in July.
"We are going to fight hard to win the primary in Washington DC," he said. "And then we take our fight for social, economic, racial and environmental justice to Philadelphia, Pennsylvania."
The White House issued a statement saying Mr Obama had called both Mrs Clinton and Mr Sanders. It said he congratulated her on securing the delegates necessary to secure the nomination, and would meet Mr Sanders on Thursday at Mr Sanders' request.
Trump 'temperamentally unfit'
In her speech, Mrs Clinton harshly attacked Mr Trump for using divisive rhetoric that belittled women, Muslims and immigrants, and took specific aim at his recent condemnation of an Indiana-born judge of Mexican heritage.
"The stakes in this election are high and the choice is clear. Donald Trump is temperamentally unfit to be president and commander-in-chief," she said.
"When Donald Trump says a distinguished judge born in Indiana can't do his job because of his Mexican heritage, or he mocks a reporter with disabilities, or calls women pigs, it goes against everything we stand for," she said.
Mrs Clinton also won in New Mexico and South Dakota. Mr Sanders won in North Dakota and Montana on the final night of big presidential nominating battles that began on 1 February in Iowa. The District of Columbia will be the last next Tuesday.
In a fundraising email to supporters, Mrs Clinton declared her campaign had broken "one of the highest, hardest glass ceilings".
On Twitter, she said: "To every little girl who dreams big: Yes, you can be anything you want - even president. Tonight is for you."
Mrs Clinton's race against Mr Trump, 69, will unfold amid an ongoing investigation of her use of a personal email server while secretary of state. Opinion polls show the controversy has hurt her ratings on honesty and trustworthiness.
A Reuters/Ipsos poll released on Tuesday showed Mrs Clinton leads Mr Trump by 10 percent nationally as they launch their general election battle, little changed from a week ago.
Mrs Clinton now must try to unify the party and win over Mr Sanders' supporters, who booed lustily in California when Mr Sanders congratulated her on her victories on Tuesday.
Mr Sanders' campaign spokesman castigated what he said was the media's "rush to judgment" after the Associated Press and NBC reported on Monday night that Mrs Clinton had clinched the number of delegates needed to win the nomination.
Mrs Clinton's victories ensured she would have a lead in the pledged delegates won in nominating contests. She cemented the nomination with the added support of superdelegates, party leaders who are free to back any candidate.
Steven Acosta, a 47-year-old teacher living in Los Angeles, voted for Mrs Clinton on Tuesday, saying that was partly because he believed she stood a better chance of winning in November.
"I like what Bernie Sanders says and I agree with almost everything that he says," Mr Acosta said. "The problem is that I think Republicans would really unify ... even more against him."
Mr Trump, who became his party's presumptive nominee last month, outlasting 16 Republican challengers, is struggling to get the party's leaders solidly behind him after a bitter primary campaign during which he made a series of controversial statements directed at Muslims, Latinos, women and the disabled.
On Tuesday night he addressed a crowd of supporters in New York, welcoming Mr Sanders' supporters "with open arms" should they decide to support him and declaring a new phase of the campaign had begun.
"I am going to give a major speech on probably Monday of next week, and we are going to be discussing all of the things that have taken place with the Clintons," he said. "I think you are going to find it very informative and very, very interesting. I wonder if the press will want to attend."
The general election will be held on 8 November.