The Arab League on Saturday froze assets of 19 top Syrian officials and banned them from traveling to Arab states.
After a meeting in Doha, Qatari Foreign Minister Sheik Hamad bin Jassim al-Thani who chairs the Arab League's peace process committee, said the panel also gave Damascus until Sunday to come to Doha and sign an initiative to end its military crackdown on protests.
Also Saturday, activists said at least 23 people had died in anti-government unrest across Syria, including violent clashes between government troops and rebel soldiers in the northern province of Idlib.
Witnesses say the battles have been intensifying in recent days as more soldiers defect from regular army units.
The latest fighting came a day after the United Nations Human Rights Council voted to condemn Syria for "gross and systematic violations of human rights" that could be linked to the government's crackdown on dissent. The U.N. body also agreed to appoint a special investigator to probe human rights abuses in Syria.
But Syria's Foreign Ministry dismissed the U.N. resolution and accused the U.N. Human Rights Council of "blatantly politicizing" it. Syria's state-run media quoted a foreign ministry official as saying the council "deliberately ignored" documents provided by the Syrian government that clarified facts.
In Istanbul Saturday, visiting U.S. Vice President Joe Biden praised Turkey for taking steps to address repression in Syria. He also joined with other world leaders in calling for Syrian President Bashar al-Assad to step down.
"Regional issues from the brutal repression in Syria where Turkey, where we stand with Turkey and a growing chorus of nations in calling for President Assad to step aside," Biden said. "And I welcome the Human Rights Council's condemnation yesterday of the regime's violence."
Earlier, a U.N.-backed study said several hundred children were among those who had been killed in the government crackdown. The world body says the overall death toll from eight months of unrest in Syria has topped 4,000.
Syria has contended its actions are not a crackdown on protests, but a necessary response to attacks by "armed terrorists" on civilians and security personnel.
Some information for this report was provided by AFP and Reuters.