Clinton won a razor thin majority over her social democratic opponent in the Bluegrass State as she picked up 46.7 percent of the vote compared to 46.3 percent for Sanders, with 99 percent of the votes counted.

With fewer than 800 votes still to be tallied, Clinton was 1813 votes ahead according to televised reports.

The lead changed hands several times during the counting of the vote on Tuesday evening in Kentucky.

Analysts said Clinton and Sanders were each set to pick up at least 25 delegates out of the state's 55 total, with five delegates still to be allocated, depending on the final vote tally. Kentucky is unusual in that the official result of the vote will only be given at the end of May.

If the Kentucky win is confirmed, Clinton remains firmly on track to clinch the Democratic nomination early next month, after leading Sanders with nearly 300 pledged delegates.

The former secretary of state also has a wide lead among party officials and elected leaders known as superdelegates.

When both figures are combined, analysts predict that Clinton would have - at least - a total of 2,265 delegates nationally, versus 1,498 for Sanders, following the Kentucky result. She needs 2,383 delegates to be the Democratic candidate.

Kentucky was not considered a favorable state for Clinton, after neighboring West Virginia and Indiana both went to Sanders. She spent the last two days campaigning in the Bluegrass State in a last minute bid to boost her support.

Sanders wins Oregon

Sanders was a clearer winner in the Oregon primary, which was also held on Tuesday.

Several US networks called the Pacific northwest state for Sanders, who was leading 53 percent to 47 percent with half of the votes counted.

Speaking to a rally of supporters in California, Sanders made it clear he would continue his campaign.

Rival Democratic candidate Bernie Sanders

Sanders defends Nevada supporters

Ahead of Tuesday's vote, Sanders leapt to the defense of violent outbursts by his supporters at a Democrat state convention in Nevada on Saturday.

A meeting to assign delegates to the national party convention in July had be shut down by security after Sanders' supporters clashed with organizers. But despite criticism of the behavior, the Vermont Senator said his backers had not been treated with "fairness and respect."

Republicans vote too

Republicans also voted in Oregon on Tuesday, with presumptive nominee Donald Trump expected to win easily.

The billionaire picked up nine delegates earlier Tuesday in Guam, which held its territorial convention in March.

Trump had 1,143 delegates heading into the Oregon contest - fewer than 100 delegates short of the 1,237 he needs to clinch the nomination.

In an interview with the Reuters news agency, the businessman said he would renegotiate the Paris climate accord, which seeks massive reductions in reduce carbon emissions.

He also said he would be willing to talk to North Korean leader Kim Jong Un to try to stop Pyongyang's nuclear program, which would be a major shift in US policy toward the isolated nation.

Trump's campaign team released a statement on Tuesday, showing his net worth had risen to $10 billion (8.8 billion euros).

mm/jm (AP, AFP)