North Liberty (US):  Mitt Romney has surged into the lead in Iowa just days before the unpredictable US state kicks off voting to decide the Republican Presidential nominee, a new poll showed.

The CNN/Time/ORC survey also confirmed Romney's dominance in New Hampshire, the second state to vote, leaving the 64-year-old former Massachusetts governor eyeing a possible fast-track romp to the nomination.

Speaking ahead of a campaign event in North Liberty, Iowa, an upbeat Romney said he was looking forward to taking on a vulnerable President Barack Obama in November 2012 if he could seal his party's nod.

"I can't wait to go head-to-head in a debate with President Obama," he told CNN. "He has failed the American people. He has failed to get this economy going."

But in a sign that the Republican race remains highly volatile and deeply uncertain, staunch conservative Rick Santorum tripled his showing from similar polls a month ago to finish third in the latest survey on 16 percent.

Romney, who was reluctant to make a big play for Iowa this time around after gambling big here in 2008 but losing out to Mike Huckabee, now finds himself in pole position as his main rival Newt Gingrich falters.

If he can take Iowa on January 3 and go on to claim an expected victory in New Hampshire a week later, it is hard to see anyone catching him despite lingering doubts among many Republicans over his conservative credentials.

The CNN/Time/ORC poll showed Romney in front in Iowa with 25 percent, narrowly ahead of Ron Paul on 22 percent. Romney's three-point margin was within the sampling error and the poll surveyed only 452 people.

Paul, a veteran Texas congressman, has a loyal following in Iowa but his libertarian views are firmly outside Republican orthodoxy and it is seen as highly unlikely that he could win the eventual nomination.

Gingrich, who enjoyed a clear lead in Iowa a few weeks ago after an unexpected popularity surge, polling as high as 33 percent, has lost ground dramatically after a barrage of negative advertising from the Romney team.

The latest poll placed him fourth on 14 percent and showed him slipping behind Santorum, a former Pennsylvania senator whose boom is likely to excite his fervent evangelical supporters.