A U.N. advance peacekeeping team is headed to Damascus to discuss deploying observers to monitor a cease-fire, a spokesman for special envoy Kofi Annan said.
The team should arrive by Thursday, Ahmad Fawzi said.
But growing reports of violence this week suggest high-level diplomatic efforts and promises by the Syrian government have yet to produce any semblance of a cease-fire.
On Monday, Syrian President Bashar al-Assad's regime promised to withdraw its forces from population centers by April 10.
But on Tuesday, government forces pounded opposition-held towns in northern Syria and battled defectors, an opposition group said
The Syrian army shelled Binnish, Taftanaz and Taoum, and its helicopters fired on fleeing civilians, an opposition activists said.
"This is the most intense fighting we have witnessed thus far in Binnish since the beginning of the revolution," said Basher, an opposition activist who uses one name. "They are using helicopters and randomly firing on civilians in the cities."
At least 74 people were killed across the country Tuesday, according to the opposition Local Coordination Committees of Syria.
Meanwhile, the state-run Syrian Arab News Agency reported that 10 soldiers, police and and civilians were buried Tuesday.
Al-Assad has promised Annan, the U.N.-Arab League special envoy to Syria, that the government would pull back his forces from cities.
The president's commitment was a response to Annan's six-point peace plan, which calls for authorities to pull their forces from and stop troop movement toward population centers and end the use of heavy weapons.
Yet "we have seen no evidence today that he is implementing any of those commitments," U.S. State Department spokeswoman Victoria Nuland said Tuesday.
Nadim Shehadi, associate fellow at the Middle East and North Africa Program of the London-based Chatham House, said Syria is playing games with the international community and "playing for time."
"I don't see them pulling out at all," he said Tuesday.
He said Syria has been trying to avoid passage of a binding and irreversible U.N. resolution that would provide for the use of force if needed, such as a Chapter VII resolution.
To date, no U.N. action has been taken that has any teeth. The regime can live with condemnation under that circumstance and can survive civil war, Shehadi said.
The Annan plan urges a cease-fire by the government and the opposition and a Syrian-led political process to end the crisis.
But countries represented at the recent Friends of Syria meeting in Istanbul staunchly support opposition forces, and envision a Syria without al-Assad at the helm.
"They are gunning for him," said Syria expert Joshua Landis, director of the Center for Middle East Studies and associate professor at the University of Oklahoma.
So one way al-Assad can slow down the effort to organize his ouster, Landis said, is backing Annan's efforts.
"Assad has negotiated this so all sides have to stop shooting," said Landis, who says he doubts there will be traction on troop withdrawal.
"The rebels will keep shooting, and the Syrian army will keep targeting them. Both sides believe they can win, and both sides believe time can be on their side," Landis said. "That doesn't promote compromise."
The Syrian regime has consistently blamed "armed terrorist groups" for violence in Syria, but most reports from inside the country suggest the government is pummeling neighborhoods in an attempt to wipe out dissidents seeking al-Assad's ouster.
Al-Assad's family has ruled Syria for more than four decades. Largely peaceful anti-government protests in March 2011 led to a violent crackdown. Some opposition members and defectors from al-Assad's regime have since taken up arms against the government forces.
The United Nations has estimated at least 9,000 people have been killed in Syria since the unrest began more than a year ago, while opposition activists have put the toll at more than 10,000.