Washington: After splitting wins in contests on Tuesday, Democrats Hillary Clinton and Bernie Sanders head into the final stretch of a longer than expected and sometimes acrimonious battle to represent their party in November's White House election.
Clinton narrowly edged out Sanders in Kentucky, a state where she had not been expected to win. Sanders won Oregon, a state that played to his strengths.
The protracted fight for the Democratic nomination has boiled over into strife in recent days, prompting party leaders to weigh in and urge unity.
The next contests will be held June 7, including in the delegate heavy states of California and New Jersey, with the final contest in Washington DC on June 14.
While Clinton is expected to win the party nomination, Tuesday's divided outcome means she is still more than 100 delegates short of sealing the deal and so cannot yet turn her attention fully to the general election and taking on presumptive Republican nominee Donald Trump.
In Kentucky, the two candidates will likely split the 55 delegates up for grabs. In Oregon, Sanders will take only a handful more of the 61 delegates that were awarded.
Trump, who locked up his party's nomination after the rest of his rivals dropped out in early May, has begun to organise his campaign for the November 8 election. On Tuesday, he signed a joint fundraising agreement with the Republican National Committee. The agreement allows him to raise $449,400 from a single donor by splitting the funds between his campaign, the RNC and state Republican parties.
Trump, a billionaire real estate developer, had so far insisted on mostly self-funding his campaign and the shift to a more traditional fundraising approach could anger some of his supporters.
In an interview on Fox News on Tuesday night, Trump said he some regrets about his actions during the Republican primary process in which he beat 16 rivals, showering insults on most of them along the way.
"I could have used different language in a couple of instances, but overall I'm happy with the outcome," Trump said.
On the Democratic side, both candidates' camps kept up a dispute on Tuesday after violent outbursts by Sanders supporters ended the Nevada Democratic convention over the weekend.
Sanders supporters were angered when Nevada state party officials chose to end their convention and block efforts to award the US senator from Vermont more delegates than he initially won in the February caucus. Clinton won the caucus.
One Sanders supporter threw a chair. Others daubed chalk graffiti on a party building. Some circulated a picture of the state party chairwoman, Roberta Lange, online with her cellphone number and encouraged others to complain.
Lange said she and her family had received death threats, including a voicemail message saying "people like you should be hung in a public execution".
On Wednesday, Democratic National Committee Debbie Wasserman Schultz slammed such actions and called for civility. "We have a process set up that is eminently fair," she told CNN. "No one should be subjected to death threats."
Senate Democratic Leader Harry Reid also said he has spoken to Sanders directly.
Sanders has said he condemns violence and harassment but leveled some of the same complaints his supporters did. He argued Lange did not allow a headcount on a disputed rules change and 64 delegates to Nevada's convention were not given a hearing before being ruled ineligible.
The state party disputed the claim, saying some delegates did not show up at the convention and others were disqualified because they were not registered as Democrats in time.
Sanders, a self-described democratic socialist who is not a registered Democrat, used the incident to boost his call for the party to allow participation by non-party members in the primary process.
Clinton's campaign continued to express confidence that she will be able to unify the party. Her campaign manager, Robby Mook, said Clinton was grateful for Nevadans who participated in the process but that no one should be intimidated, harassed or threatened. our party must come together and ensure a Democrat is elected to serve as our next president."