US President Barack Obama and Republican foe Mitt Romney battle over foreign policy Monday in their last debate of a White House race that is deadlocked with two weeks to go.
The rivals faced a final chance to land a decisive blow in front of millions of television viewers, before a last-ditch dash for votes in a bitter campaign that has exposed the sharp political divide splitting America in two.
They were expected to duel over policy on Libya, China, Afghanistan, Syria and Iran's nuclear program, though will likely produce more political heat than insight into how either of them would run US diplomacy in the next four years.
Foreign policy is unlikely to decide who wins on November 6, with the economy driving the election, but Romney is under pressure to show basic competence as a potential commander-in-chief following a string of blunders.
Obama enters the debate in swing state Florida with his longtime polling advantage under siege. Romney is nosing ahead in national polls and eroded Obama's foundation in the battleground states that will decide the election.
Romney won the first debate after a lethargic performance from Obama but the president's feisty showing on Long Island, New York last week meant he emerged with honor restored, leaving the third debate as a tie-breaker of sorts.
Both the foes toured the debate venue at the Lynn University, where they will sit at a table with moderator Bob Schieffer, a veteran CBS news anchor, in a set up which will rule out their predatory prowling of the second debate.
Sticking to a winning formula from the second debate, Obama and First Lady Michelle Obama planned to dine on steak and potatoes. Romney earlier lunched on a veggie burger, with Cajun fries washed down with a vanilla shake.
Vice President Joe Biden, campaigning on Monday in Ohio, which is looming as the kingmaker state, suggested Obama would accuse his rival of inconsistency, a theme which he has already used to attack Romney's domestic policy.
"The differences are profound on foreign policy," Biden said, attacking Romney and his running mate Paul Ryan on Afghan war strategy.
"The President and I have made it absolutely clear we will leave Afghanistan in 2014. Period.
"Governor Romney and Congressman Ryan, they have made it clear they are willing to stay -- 'we can leave in 2014, maybe -- it depends.' It depends on what day you find these guys," Biden said.
Romney will likely make a new attempt to trip Obama over his administration's shifting stories on the attack on the US consulate in Benghazi, Libya on September 11 which killed four Americans.
The Republican has squandered several chances to jump Obama on the issue, after a hasty statement early in the crisis and a stumble in the last debate over the president's characterization of events in Benghazi.
Republicans claim Obama was reluctant to admit the attack was an act of terrorism, fearing am al-Qaeda comeback it would knock him off his pedestal as the commander-in-chief who had put the militants on the run.
Top administration officials at first said the attack was a spontaneous act that arose out of a demonstration against an anti-Muslim video.
Later assessments blamed heavily armed militants, but officials say the incident still seems more opportunistic than pre-planned.
Reports in The Wall Street Journal and New York Times may have given Obama some breathing room Monday, finding top aides based their early conclusions on the attack on CIA talking points and not on political spin.
Romney is likely to use the debate to press his point that the Libya attack is a symptom of an unraveling Obama foreign policy.
But the former businessman is more comfortable addressing economic problems than international issues and his foreign tour earlier this year, meant to show the readiness of a statesman, was widely panned.
Obama also has issues: a Pew Research Center poll shows his advantage on foreign policy shrinking to just four points over Romney, after being up 15 points last month.
At the debate, beginning at 9.00pm EST (0100 GMT), the president will remind Americans he kept his promise to end the Iraq war, is getting troops out of Afghanistan and ordered the raid that killed Al-Qaeda chief Osama bin Laden.
He may also claim his rival is a throwback to the era of president George W. Bush, when Washington was better getting into foreign wars than out of them.
Both camps say their candidates will draw discussion back to the issue most pressing for voters -- the economy.
The Republican will seek to pressure on Obama over Iran's nuclear program, arguing that presidential weakness has emboldened Tehran.
Obama has in the past reacted furiously to Romney's claims he was "appeasing" Tehran.
Complicating the scenario, the Times reported Saturday that US officials said Iran was ready for one-on-one talks with Washington, though the White House denied the report.
Rattled Democrats got some good news on Monday, with a new CBS News/Quinnipiac University survey putting Obama up five points in Ohio.
Other polls have the state race tighter however and the race is too close-to-call across the battleground.