Sen. Lindsey Graham, a Republican member of the Senate Foreign Affairs Committee, said President Trump's phone call to Khalifa Haftar, a longtime Libyan warlord who is spearheading an effort to topple the North African country's United Nations-backed government, had an "unnerving" effect in the region.

"I don't know what the phone call to Haftar was about, but it had an unnerving effect on the ground," Graham said on "Face the Nation" Sunday, adding later that the "phone call seems to be perceived in the region as we're picking sides."

Graham, one of the most vocal advocates of an active U.S. role abroad, said supporting a faction in Libya's prolonged internal conflict, which ensued after the U.S.-backed ouster and killing of strongman Moammar Gadhafi in 2011, could precipitate a full-blown civil war similar to the situation in Syria.

"There is no way General Haftar can take Tripoli and hold it," Graham added, referring to Libya's capital and largest city. "The prime minister supported by the U.N. is supported by Turkey and Qatar. And if we pick sides, you're going to create the Syrian situation on the ground in Libya. So my advice to the president is push for a political reconciliation in Libya. There is no military solution to Libya. Haftar cannot control the country by military force."

Haftar, a U.S. citizen and former resident of Virginia, has signaled he might move his troops into Tripoli and take the city by force.

Graham urged the president to pursue a "political solution" in Libya, warning that an escalation of violence would lead to more refugees fleeing the country.

"I hope we rebalance that phone call soon," he said.