Former New Mexico Gov. Bill Richardson and former House Speaker Newt Gingrich both said Sunday that Libya is a strong point of contention on foreign policy - the subject of Monday night's presidential debate - but argued over which candidate has more leverage on the topic.

Speaking on CNN's "State of the Union," Gingrich said the Obama administration's handling of last month's attacks on the U.S. Consulate in Benghazi, Libya, which resulted in the deaths of four Americans, will be a tough record to defend.

In last week's debate, President Barack Obama took responsibility for the security of State Department personnel, saying ultimately the buck stops at his desk. "That's why nobody's more interested in finding out exactly what happened than I do," the president said.

Gingrich pointed to Obama's words and criticized the lack of robust security at the U.S. Consulate in Benghazi, adding the whole episode represents a larger narrative of the president's foreign policy track.

"If we can't figure out what went on in a relatively open city in a country we had helped liberate, why do we think we know what's going on with Iran's nuclear program?" the former Republican presidential candidate said.

He continued: "I think you can go country by country and see some of the fraying at the edges of the Obama policy."

Richardson, however, described GOP nominee Mitt Romney as being unprepared for the Oval Office, specifically citing his widely criticized initial response to the violence. Romney's campaign put out a statement the night of the Libya consulate attack, as well as the breaching of the U.S. Embassy in Cairo. The following morning, Romney held a press conference, attacking Obama on foreign policy. Democrats and some Republicans criticized the response as one that was hastily made.

"Gov. Romney just seems to be bluster, blunder, cowboy-alone foreign policy," Richardson, a Democrat, told CNN chief political correspondent Candy Crowley. "I'm troubled at this time when we had the Benghazi crisis, he's trying to make political gain."

The former governor, who also served U.S. ambassador to the United Nations, argued Obama had made progress in the Middle East in the last four years, pointing to the killing of Osama bin Laden and renewed military focus on Afghanistan.

Richardson said the president has a major "advantage when it comes to foreign policy."