WASHINGTON - Republican challenger Mitt Romney has extended his lead over US President Barack Obama to 3 percentage points, according to a Reuters/Ipsos tracking poll released on Thursday, ahead of a high-stakes debate between the two candidates' running mates.

Romney now leads the Democrat by 47 percent to 44 percent among likely voters in the online poll, with less than a month before the Nov. 6 election. The Reuters/Ipsos tracking poll released on Wednesday had shown Romney with a one-point lead over Obama, his first lead in the survey in more than a month.

Romney has been enjoying one of his best runs of the campaign after handily winning the first presidential debate last week, partially due to Obama's passive performance in that contest.

Please LIKE our Facebook page - it makes us stronger