Hillary making history as US votes in last big primaries

Americans from New Jersey to California cast ballots on Tuesday in the final major primaries of the 2016 White House race, after delegate counts showed Hillary Clinton clinching the Democratic nomination.

Democratic presidential candidate Hillary Clinton arrives on stage for a rally at Long Beach City College on the final day of California campaigning.

The results are expected to see Clinton declare victory as the first woman in history to secure the presidential nomination of a major US party, putting her on course for a showdown with New York billionaire Donald Trump, the presumptive Republican nominee, in November's election.

Her challenger Bernie Sanders has so far ignored media reports that she has clinched the magic number of delegates. The self-declared democratic socialist is chasing a win in the country's largest state California, and insisting the nominee will not be chosen until the party convention in July.

Voting was underway in six states - California, New Jersey, New Mexico, Montana, North Dakota and South Dakota. New Jersey and the Dakotas will be the first polls to close at 20:00  Eastern time (00:00 GMT Wednesday).

It remained unclear what effect the reports that Clinton had passed the milestone of 2 383 delegates Monday would have on those casting ballots.

"I'm a Bernie Sanders guy all the way." said 21-year-old student Saul Gomez, voting in Los Angeles. "Honestly he seems a lot more genuine to me," he said.

"He's consistent, and I dig that." Clinton - the 68-year-old former first lady, New York senator and for four years President Barack Obama's top diplomat - is scheduled to deliver a speech in Brooklyn late on Tuesday in perhaps the pinnacle of her political career to date.