BOCA RATON, Fla (AP) - President Barack Obama has sharply challenged Mitt Romney on foreign policy in their final campaign debate Monday night in Boca Raton, Fla.

Romney went on the offensive, too. When Obama said the U.S. and its allies have imposed crippling sanctions on Iran to halt nuclear weapons development, the Republican challenger responded that the U.S. should have done more. He said repeatedly, ``We're four years closer to a nuclear Iran.''

Romney also said the U.S. Navy has fewer ships than it did in 1916. Obama responded that there also are ``fewer horses and bayonets'' and ``things called aircraft carriers where planes land on them.''

The two men found accord on more than one occasion when it came to foreign policy. Romney applauded the killing of Osama bin Laden. Each stressed unequivocal support for Israel when asked about a U.S. response if the Jewish state were attacked by Iran. Both also said they oppose direct U.S. military involvement in the efforts to topple Syrian President Bashir Assad.

And while the focus of the final faceoff was to have been primarily on foreign policy, both candidates took the liberty of shifting questions to talk about domestic policy.