Hillary Clinton and Donald Trump. Pics/AFP

Washington: A week before the US presidential elections, Republican nominee Donald Trump has taken a slender lead of one percentage point against his Democratic rival Hillary Clinton for the first time since May in a major national tracking poll.

Trump has overtaken Hillary in the ABC News/Washington Post tracking poll, according to which the Republican candidate has the support of 46 per cent of the likely voters as against 45 per cent by the former secretary of state.

"Strong enthusiasm for Hillary has lost seven points since the start of tracking, especially Friday through Sunday. This is possibly an after-effect of the renewed controversy over her use of a private email server while secretary of state. Trump's strong enthusiasm has held steady in tracking, which started October 20," the poll said.

According to the poll, Trump now leads Hillary by eight points in the share of voters who are very enthusiastic about their choice as of Friday. But, compared to past elections it's low for both of them - 53 per cent for Trump, 45 per cent for Hillary, it said.

Till about two weeks ago, Hillary was leading Trump by more than eight points in this average of polls. However, a reliable election model predicted a win for Hillary in the elections.