Republican presidential nominee Donald Trump posted a two-point lead over his Democratic rival Hillary Clinton in a poll, the first time he has been ahead since early May.

Mr 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.

Meanwhile, Mrs Clinton's nomination in Philadelphia this week was marred by party divisions and the resignation of top party official Debbie Wasserman Schultz following email leaks.

Sorry, this video has expired Triumphant Donald Trump pledges "I am your voice" in his nomination acceptance speech.

The July 22-26 Reuters/Ipsos opinion poll found that 39 per cent of likely voters supported Mr Trump, 37 per cent supported Mrs 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.

Mrs Clinton last week held a three-point lead, which was also within the credibility interval.

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

Democrats hope for poll boost after convention

In early May, Mr Trump briefly pulled even with Mrs 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.

Mr 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.

The Democratic Party is hoping for a boost in the polls during its convention this week in Philadelphia, but the confab had a rough start: the WikiLeaks website released emails showing that party officials had looked for ways to undermine the candidacy of Mrs Clinton's rival for nomination Senator Bernie Sanders.

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

On Tuesday (local time), some speakers at the Democratic convention were booed by Sanders supporters, and hundreds of protesters took to the streets to protest Mrs Clinton's candidacy.

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

In 2012, Republican nominee Mitt Romney jumped by 5 percentage points to pull about even with President Barack Obama after the Republican convention.

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

The Reuters/Ipsos poll was conducted online in English with about 962 likely voters.

Reuters