U.S. lawmakers are calling on the Obama administration to ratchet up pressure on Syrian President Bashar al-Assad, with one prominent senator urging the president to put military force on the table as the regime launches an all-out assault on protesters. 

Sen. Lindsey Graham said in an interview over the weekend that Assad's actions are now "indistinguishable" from Muammar al-Qaddafi's, the Libyan leader whose threats and attacks against his own people triggered NATO's military campaign against his regime. 

Hundreds are now dead in Syria, and brutal new video has emerged purporting to show Syrian soldiers beating protesters. A military campaign in the northern part of the country sent civilians fleeing by the thousands to a refugee camp in Turkey. 

"It's wholesale slaughter now," Graham, R-S.C., said. "The reason we went into Libya is to protect the Libyan people from wholesale slaughter. When they protested, Qaddafi started killing them in the streets. He took his army, turned them on his own people. That's exactly what's happening in Syria." 

But U.S. officials and analysts have warned, despite the similarities in their brutality, Syria and Libya are very different. Qaddafi was already relatively isolated before he started attacking his own people, whereas Assad's regime is far more entrenched in the region and its politics. 

Importantly, an international coalition quickly assembled to enforce the United Nations resolution against Libya. White House Press Secretary Jay Carney on Monday implicitly cited the absence of such a coalition as he tried to explain why no nation has stepped forward to stop Assad. 

"There are different circumstances," Carney told reporters. "We had a United Nations mandate (with Libya). We had a broad coalition that was eager to participate in a mission that was designed to prevent the immediate carnage that would have taken place in Benghazi, to protect civilians from the grave danger presented by Qaddafi's forces, to enforce an arms embargo and to enforce a no-fly zone." 

Still, Carney reiterated that President Obama is calling on Assad to "cease the violence" and condemns Assad's actions "in the strongest possible terms." 

"The president has made clear that President Assad needs to engage in political dialogue, that the transition there needs to take place towards more political freedom, and that if President Assad does not lead that transition then he should step aside," he said. 

The U.S. and its allies are pursuing other ways to apply pressure to the regime. After pushing sanctions of its own, the U.S. is backing a U.N. Security Council resolution pushed by European nations that condemns the crackdown. The U.S. also successfully urged the International Atomic Energy Agency to report the country to the Security Council over its nuclear program. 

Graham -- along with Sens. John McCain, R-Ariz.; Joe Lieberman, I-Conn.; Bob Casey, D-Pa.; and Marco Rubio, R-Fla. -- applauded the administration over the weekend for the IAEA decision, claiming it puts needed pressure on Assad. 

However, given the military response of Assad against the protesters, they said, "the response of the United States and the international community has not been commensurate with the evils taking place in Syria." 

They urged Obama and Secretary of State Hillary Clinton to publicly call for him to step down, and they said other measures should be considered, like expelling Assad's U.S. ambassador. 

Graham, on CBS' "Face the Nation," also recommended an international aid effort for the Syrian people -- and more regional cooperation overall, while keeping military force on the table. 

But with the U.S. expected to spend more than $800 million by September on Libya and Defense Secretary Robert Gates publicly criticizing NATO partners for not doing enough, there may be little appetite in Washington for opening up another military front for America's stretched forces. 

The House of Representatives earlier this month chided Obama for his handling of the Libya operation, and the Senate is considering doing the same. 

Retired Gen. Jack Keane, former vice chief of staff for the Army and a Fox News military analyst, said the military option should be on the table but that the U.S. can apply pressure elsewhere to "isolate" the Assad regime. 

"They have business interests around the world. There's ... lots of pressure we can bring to bear," he said. "It would not change the immediate behavior of the Assad family in terms of preserving the regime, but it would create fractures and fissures in those that are supporting them." 

Keane said authoritarian regimes in the Middle East have drawn a dangerous lesson from the turmoil in the region -- in Egypt, Hosni Mubarak succumbed to protesters' demands and resigned; in Libya, Qaddafi sought to "clear the streets at all costs," he said. 

"Obviously, Mubarak fell. They look at that and say to themselves, 'clear the street at all costs.'" Keane said.