U.S. President Barack Obama and his Republican challenger Mitt Romney have battled over national security in the third and final presidential debate. The rivals tangled over the Arab Spring, Iran, China's rise and more in a feisty 90-minute head-to-head, BBC News reports.

Obama said his challenger was "all over the map" on foreign policy, while Romney said the president had failed to uphold American global leadership.

The rivals, meanwhile, found some common ground - each declared unequivocal support for Israel and both voiced opposition to U.S. military involvement in Syria.

Romney also said he agreed with the president's policy of withdrawing troops from Afghanistan by 2014 - the Republican has suggested otherwise in the past.

In laying out one of his overarching themes on foreign policy, Romney said the U.S. under President Obama's leadership had allowed "tumult" to engulf the Middle East. He cited civilian deaths in Syria, the rise of al-Qaeda affiliates in North Africa and Iran's nuclear program.

But the Republican steered clear of his suggestion in the last debate that the Obama administration had mishandled last month's Libya U.S. consulate attack, which left four Americans dead.

"What's been happening over the last couple of years is, as we're watching this tumult in the Middle East, this rising tide of chaos occur, you see al-Qaeda rushing in, you see other jihadist groups rushing in," Romney said.

Obama hit back that he was glad that Romney had recognized the threat posed by al-Qaeda, reminding the former Massachusetts governor that he had earlier this year cast Russia as America's number one geo-political foe.

The president sought to portray Romney as a foreign policy novice who lacked the consistency needed to be commander-in-chief.

Obama said Romney had backed a continued troop presence in Iraq, opposed nuclear treaties with Russia, even when they had broad bipartisan backing, and accused the Republican of flip-flopping over whether the U.S. should have a timeline for leaving Afghanistan.

"What we need to do with respect to the Middle East is strong, steady leadership, not wrong and reckless leadership that is all over the map," Obama said.