A new poll says U.S. President Barack Obama and presidential challenger Mitt Romney are tied ahead of their third and final debate Monday.

The NBC News/Wall Street Journal poll showed support for the candidates among likely voters at 47 percent each.

Monday's 90-minute debate in the closely contested state of Florida will focus entirely on foreign policy and will be moderated by Bob Schieffer of CBS news.

Mr. Romney and his Republican allies have continually attacked President Obama for his handling of last month's deadly attack on the U.S. consulate in Libya. The September 11 attack in Benghazi killed U.S. ambassador Christopher Stevens and three other Americans.

Iran's nuclear program has also been a subject of contention, with Mr. Romney saying the Obama administration has not been tough enough on Tehran and not supportive enough of Israel.

Mr. Obama has accused Mr. Romney of politicizing the attack in Libya, and said he has put in place tough sanctions on Iran while building U.S. security cooperation with Israel. The president has also highlighted anti-terrorism successes, including the raid that killed Osama bin Laden.