Republican presidential nominee Donald Trump has posted a two-point lead over his Democratic rival Hillary Clinton, according to the latest opinion poll released on Tuesday.

Trump's gains came as he accepted his party's nomination to the November 8 ballot at the four-day Republican National Convention in Cleveland last week, and as Clinton's nomination in Philadelphia this week was marred by party divisions and the resignation of a top official.

It is the first time Trump has been ahead since early May.

Ahead: Republican presidential nominee Donald Trump posted a two-point lead over his Democratic rival

The July 22-26 Reuters/Ipsos poll found that 39 per cent of likely voters supported Trump, 37 per cent supported Clinton and 24 per cent would vote for neither.

The poll had a credibility interval of four percentage points, meaning that the two candidates should be considered about even in support.

Clinton held a three-point lead on Friday, which was also within the credibility interval.

Clinton has solidly led Trump in the poll throughout most of the 2016 presidential race. The only times that Trump has matched her level of support were when the Republican Party appeared to be roughly aligned with his campaign.

In early May, Trump briefly pulled even with Clinton after his remaining rivals for the party nomination dropped out of the running. He held a 0.3 percentage point lead over Clinton on May 9, the last time he was nominally ahead.

Trump fell back in the poll as he feuded with party bosses over comments he made about Hispanics, Muslims and immigrants, but he rebounded this month as his candidacy took the national spotlight at the Cleveland convention.

Clinton, pictured on a screen at the Democratic National Convention, has solidly led Trump in the poll throughout most of the 2016 presidential race

The Democratic party is hoping for a similar boost during its convention this week in Philadelphia, but the confab had a rough start: the Wikileaks website released emails on Friday that enraged many voters who had supported Clinton's rival for the nomination, Senator Bernie Sanders of Vermont, showing that party officials had looked for ways to undermine his candidacy.

The chair of the Democratic National Committee, Debbie Wasserman Schultz, announced her resignation afterward.

On Monday, some speakers at the Democratic convention were booed by Sanders supporters, and hundreds of protesters took to the streets to protest Clinton's candidacy.

Presidential candidates usually get a boost in popularity following their party conventions.

In 2012, Republican nominee Mitt Romney jumped by five percentage points to pull about even with President Barack Obama after the Republican convention.

After the Democrats held their convention, Obama then rose by a few percentage points and again pulled ahead.