Clinton campaigns in Kentucky
Clinton campaigns in KentuckyReuters

Hillary Clinton is narrowly ahead of rival Bernie Sanders in Kentucky's Democratic presidential primary with 99 percent of the vote counted on Tuesday night, Reuters reports.

While some American media outlets have declared Clinton the winner in Kentucky, others are saying the race remains too close to call.

Kentucky was not considered favorable terrain for Clinton, after neighboring West Virginia and Indiana both went to Sanders, noted Reuters. But Clinton's ability to stave off a resounding defeat in Kentucky now gives her a little breathing room, as she looks forward to a lull in the primary campaign before the final contests on June 7.

Clinton, who spent the past two days campaigning in Kentucky, would like to lock up the nomination and turn her attention to November's general election and presumptive Republican nominee Donald Trump, noted the news agency.

Clinton's sizeable lead in delegates means it is likely she will eventually be her party's nominee, but she remains more than 100 delegates short of sealing the deal.

A Democratic primary was also held in Oregon on Tuesday. For the Democrats, there are 55 delegates up for grabs in Kentucky and 61 in Oregon. All of the delegates are awarded proportionally, meaning the results could do little to upset the current trajectory of the Democratic race.

With respect to the race for the White House, a poll last week found that Trump's support has surged and he is now running nearly even with Clinton among likely U.S. voters.

In the survey, 41 percent of likely voters supported Clinton, and 40 percent backed Trump, with 19 percent not decided on either yet.

The poll followed a Quinnipiac University poll released days earlier and which found that Clinton and Trump are neck and neck in the key states of Pennsylvania, Ohio and Florida.