BOCA RATON, Florida: Barack Obama and Mitt Romney spend the weekend hammering out their foreign policy battle lines ahead of their final debate, dropping off the campaign trail and dispatching their running mates to court voters in battleground states.

The debate, which focuses on international affairs, will be the final chance for each to lay out his policy platforms and engage in verbal jousting in front of tens of millions of TV viewers just 15 days before voters head to the polls.

With both sides conceding that the race to November 6 will go down to the wire, and amid a consensus that each candidate won one of the previous two debates, the stakes for Monday’s (Tuesday in Manila) clash are enormous.

And just as they study up on the particulars of US policy about the Middle East, China and Russia, the New York Times reported a possible breakthrough on talks with Iran—a report quickly squelched by the White House.

Citing unnamed administration officials, the Times reported that Iranian officials had agreed to direct US-Iran talks over Tehran’s nuclear program, after years of secret talks between the two sides.

The Iranians insisted that such negotiations wait until after the US election, when they will know who the next president will be, the report said.

The White House swiftly denied any deal had been reached, saying it was still working on a “diplomatic solution.”

“It’s not true that the United States and Iran have agreed to one-on-one talks or any meeting after the American elections,” National Security Council spokesman Tommy Vietor said in a statement.

The Times story broke just as the two US candidates were hunkered down for debate prep.

Obama was gathering his team at Camp David, the remote presidential retreat in Maryland’s Catoctin Mountains, while Romney opted for a bit of sun, heading to a beach-side resort in debate site Boca Raton, Florida, where he is huddling with top strategists.

The challenger also took the opportunity to hit up wealthy donors one last time. Romney attended his final fundraising event of the campaign Saturday in Palm Beach, an aide said.

Obama attended his final fundraiser earlier this month.

With the candidates off the trail, it was up to their deputies to sway voters.

Vice President Joe Biden was in Orlando, Florida, where he ducked into a campaign field office to energize volunteers before heading to an event in St. Augustine.

The Republican ticket is placing a similar premium on the Sunshine State. Romney and running mate Paul Ryan shared the stage on Friday at a rally in Daytona Beach.

Obama has caught flak from Republicans for not articulating a clear vision for the next four years.

For their part, Obama supporters attack Romney for not revealing details of which loopholes or deductions he would close or end in order to pay for his planned 20 percent tax cut.

Just over two weeks remain and polls show the candidates neck and neck, with battlegrounds Florida, Ohio and Virginia proving crucial.