Presumptive Republican presidential nominee Donald Trump has narrowed the gap to within 3 percentage points of his Democratic rival Hillary Clinton, according to a new poll.

Trump has gained 2 points on Clinton in the past week, a national tracking poll from NBC News has found.

Trump has already closed to within the margin of error in a Reuters poll released Thursday, trailing her by an average of just 1.2 percentage points.

In a general election match-up, Clinton has much more support than Trump with blacks and Hispanics, leading him with those groups by 75 to 37 percent.

Trump, however, has more support among white voters by 14 points, a number large enough to cancel out his deficit among the smaller numbers of minority ballot-casters.

Gender appears to be even more crucial than race in the polling numbers, however.

Clinton is leading Trump by 15 points among women. Trump's 11 point edge among men isn't enough to erase the gap.

That same four-percent gap between the Democratic edge with women and the Republican advantage with men played out in the 2012 presidential election, with Barack Obama occupying the same position Clinton is in today.

Clinton also leads Trump among college-educated voters and those from the poorest households. Trump outperforms her among less-educated groups, and in households that earn more.

The NBC News poll also found Republican voters trust Trump more than US House of Representatives Speaker Paul Ryan to lead the GOP.

Ryan, the Republicans' vice presidential nominee in 2012, has said he is not yet ready to endorse Trump or embrace his policy goals. The two men met in Washington last Thursday.

Even though Trump and Clinton are gearing up for the general election, they still need to amass the required number of delegates to secure their respective nominations.

Clinton needs an additional 143 delegates to reach the required 2,383 to secure the nomination. Trump needs 1,237 delegates to clinch the nomination. ABC News estimates that he currently has 1,143.

The states of Oregon and Kentucky will hold their primary elections on Tuesday.

US Democratic presidential candidate Bernie Sanders is hoping to keep his campaign alive with strong showings in the Kentucky and Oregon primaries.

Sanders recently won primaries in Indiana and West Virginia, but that did not help him cut into Clinton's delegate lead. But Sanders has argued that he still has a path to the Democratic nomination.