(AP Photo/Susan Walsh, File)

WASHINGTON - Amid fresh violence in Syria, President Barack Obama called on the U.N. Security Council on Saturday to stand up against Bashar Assad's "relentless brutality" and act as a credible advocate for human rights.

In a blistering statement, Obama said Assad had displayed "disdain for human life and dignity" following weekend attacks in the city of Homs that activists say left more than 200 people dead.

"The Syrian regime's policy of maintaining power by terrorizing its people only indicates its inherent weakness and inevitable collapse," Obama said. "Assad has no right to lead Syria, and has lost all legitimacy with his people and the international community."

To the Syrian people, Obama pledged U.S. support and vowed to work with them to build a better future in their country.

The president's statement came as the Security Council was meeting in New York for an unusual weekend session to consider a draft resolution backing an Arab League call for the Syrian leader to step down. The U.S. and other western nations strongly support that resolution, but it faces the prospect of a Russian veto.

Obama urged the Security Council to take a stand against Assad's regime and back the resolution.

"The international community must work to protect the Syrian people from this abhorrent brutality," he said.

The Obama administration has long called for Assad to leave power during the 11-month crackdown on the uprising against his regime. But the U.S. has ruled out military action to oust Assad.

The U.N. said in December that that more than 5,400 people have been killed since March, but it has been unable to update its count for weeks due to the chaos. Hundreds more have been killed since that tally was announced.