Republican presidential nominee Donald Trump has closed in on his rival, Hillary Clinton, in the latest national tracking poll from Reuters/Ipsos.

Mr Trump trailed Ms Clinton in all of the major polls throughout the week, but results released on Friday appear to indicate the presidential race may be much closer than once believed.

The poll found that 40 per cent of likely voters support Mr Trump, while 39 per cent back Ms Clinton for the week of 26 August through 1 September. Ms Clinton’s lead has declined from an eight-point lead, according to Reuters.

Mr Trump’s favour among Republicans has also bounced six percentage points to 78 per cent over the past two weeks, despite controversial staff shake ups and his seemingly wavering stance on immigration. In a major policy speech on Wednesday, Mr Trump seemed to win back enthusiasm as he vowed to deport millions of undocumented immigrants during his “first hour” as president.

But Mr Trump still lacks the party support held by Mitt Romney in 2012, who had 85 per cent of support from Republicans at this stage in the election.

The Friday poll comes amid news that the FBI released details of Ms Clinton’s interview with investigators regarding emails kept on her private servers – an issue that has plagued the Clinton campaign from the onset.

Donald Trump: There will be no amnesty

Ms Clinton has been accused of mishandling classified information while working for the State Department, but the report attributes her mismanagement of the emails to a concussion suffered in 2012.

“Clinton said she received no instructions or direction regarding the preservation or production of records from State [Department] during the transition out of her role as Secretary of State in 2013,” the documents read.

“However, in December of 2012, Clinton suffered a concussion and then around the New Year had a blood clot,” it adds. “Based on her doctor’s advice, she could only work at state for a few hours a day and could not recall every briefing she received.”