An FBI reinvestigation into Democratic presidential candidate Hillary Clinton's use of a private email server while as secretary of state turned up nothing that merits criminal charges, FBI director James Comey said Sunday.

The announcement is a boon to Clinton who has seen her lead over her Republican rival Donald Trump dwindle since the FBI announced a reinvestigation of the email scandal on Oct. 28, just 11 days before the Nov. 8 election.

"We have not changed our conclusions that we expressed in July with respect to Secretary Clinton," Comey said in a letter sent to members of Congress, referring to the FBI's decision in July to bring no charges against her, according to media reports.

With just two days left before the election, Clinton and Trump were neck-and-neck with Clinton leading only by 1 to 5 percentage points within margins of error, according to voter surveys by major newspapers and TV stations.

Countries around the world, especially allies like South Korea, are closely watching the race as the results can have profound impacts on their security and economic relations with the most powerful nation in the world. (Yonhap)