Support for Donald Trump has surged and he is now nearly neck-and-neck with Democrat Hillary Clinton among likely US voters.
As recently as last week, Clinton led Trump by around 13 points in the poll, but the latest Reuters/Ipsos poll released on Wednesday shows a dramatic turnaround since Trump became the Republican party's presumptive presidential nominee.
The results signal a close fight between the two likely White House rivals as Americans make up their minds ahead of the November 8 election to succeed Democratic President Barack Obama.
In the most recent survey, 41 per cent of likely voters supported Clinton, the Democratic front-runner, and 40 per cent backed Trump, with 19 per cent not decided on either yet, according to the online poll of 1289 people conducted from Friday to Tuesday.
The poll had a credibility interval of about three percentage points.
The results reflect a big increase in support for Trump since he knocked out US Senator Ted Cruz of Texas and Ohio Governor John Kasich last week to become the last Republican in the White House race.
