Syria's president has promised to do all he can to ensure UN envoy Kofi Annan's peace plan for his country succeeds, but demanded a pledge from his opponents to halt violence.
His call came as rebels carried out a string of bold attacks, killing two army colonels and kidnapping a high-ranking pilot.
Bashar Assad's condition of an express promise from the opposition to stop attacks could complicate Annan's attempts to bring an end to more than a year of violence that the UN says has killed more than 9,000 people.
The opposition has cautiously welcomed Annan's six-point plan, which calls for Assad's regime to implement a cease-fire.
But the opposition is also deeply sceptical Assad will carry it out, believing he has accepted the plan just to win time while his forces continue their assault to crush the uprising. Armed rebels are unlikely to stop fighting unless offensives by security forces halt.
The diplomatic moves came as Arab leaders met in the Iraqi capital Baghdad in their annual summit and were expected to issue a resolution backing Annan's plan.
In speeches at the summit, many leaders made clear they felt the burden was on Assad's regime to halt the fighting.
"The Syrian government is required today to listen to the voice of reason and wisdom and stop all kinds of violence," the emir of Kuwait told the gathering.
In comments carried on Syria's state news agency, Assad said: "Syria will spare no effort to make (Annan's) mission a success and hopes it would return security and stability to the country."
But he added that Annan must also get a commitment from armed groups to cease their "terrorist acts" against the government.
Throughout the crisis, Assad's regime has held that it faces not a popular uprising against his rule but a campaign of violence by terrorists.
Syria's uprising began a year ago with peaceful protests against Assad, which were met with a fierce crackdown by security forces.
Since then, army defectors and protesters who took up weapons have formed militias, initially to protect protesters. But as the bloodshed rose, they turned to seizing pro-opposition neighbourhoods, towns and areas and launching attacks on government forces, usually raids on checkpoints or on army convoys.
The new attacks today were particularly bold.
In Aleppo, Syria's largest city, gunmen opened fire on two army colonels in the central Bab al-Hadid roundabout, killing them. The state news agency SANA said the four attackers belonged to an "armed terrorist group."
In eastern Ghouta, a suburb a few kilometres (miles) from Damascus, gunmen kidnapped the pilot, a brigadier, while on his way to work,
Rebels also attacked an army truck and killed two soldiers in the central province of Hama, activists said.
Fresh clashes also broke out between government troops and army defectors in the north and south, and activists said security forces reportedly killed at least 16 civilians across Syria, including a child and two women.
SANA said authorities successfully liberated five military personnel who it said were kidnapped earlier by an "armed group" in the northern province of Idlib.