Syrian President Bashar al-Assad has declared that his country was at war and ordered his new government to spare no effort to achieve victory.
Mr Assad was speaking as the worst fighting of the 16-month conflict reached the outskirts of the capital.
Video published by activists recorded heavy gunfire and explosions in suburbs of Damascus.
Syria's state news agency SANA said "armed terrorist groups" had blocked the old road from Damascus to Beirut.
The declaration that Syria is at war marks a change of rhetoric from Mr Assad, who had long dismissed the uprising against him as the work of scattered militants funded from abroad.
"We live in a real state of war from all angles," Mr Assad said in a speech broadcast on state television.
"When we are in a war, all policies and all sides and all sectors need to be directed at winning this war."
Reports from Syria cannot be independently verified as state authorities have barred international journalists and rights groups.
Mr Assad also commented on subjects as far afield as the benefits of renewable energy, but left little room for compromise.
He denounced the West, which "takes and never gives, and this has been proven at every stage".
The United Nations accuses Syrian forces of killing more than 10,000 people during the conflict, which began with a popular uprising and has built up into an armed insurgency against four decades of rule by Mr Assad and his father.
The UN peacekeeping chief said it was too dangerous for a UN observer team, which suspended operations this month, to resume monitoring a ceasefire.
The truce, part of a peace plan backed by international envoy Kofi Annan, has long since been abandoned in all but name.
The Syrian Observatory for Human Rights, a group which compiles reports from rebels, said 115 people were killed across Syria today, making it one of the bloodiest days of the conflict.
Its toll included 74 civilians it said had been killed, including 28 in Qudsiya.
It described heavy fighting near the headquarters of the Republican Guard in Qudsiya, and in other Damascus suburbs of al-Hama and Mashrou' Dumar, just 9km from the capital.
SANA said dozens of rebels were killed or wounded and others arrested in fighting on the old Beirut road.
Government forces seized rocket launchers, sniper rifles, machine guns and a huge amount of ammunition, it said.
NATO condemnation
Earlier, NATO member states condemned Syria for its shooting down of a Turkish military jet, calling it "unacceptable".
The organisation demanded that Damascus take steps to prevent further incidents.
Ambassadors of NATO's 28 member states met in Brussels to consult with Turkey on Friday's incident.
NATO Secretary-General Anders Fogh Rasmussen said NATO security was "indivisible".
However, he said NATO's Article 5, which calls for member states to see an attack on one country as an attack on all the alliance's members, had not been discussed.
NATO met for consultations on a request from Turkey.
Syria said the shooting down was self-defence but Ankara branded the incident an "act of aggression".
Turkey has rejected assertions from Syria that its forces had no option but to fire on the F-4 jet as it flew over Syrian waters close to the coast on Friday.
It is only the second time in NATO's 63-year history that it has convened under Article 4 of its charter. The first time was in 2003 to discuss the Iraq war, again at the request of Turkey.
Article 4 provides for consultations when a member state feels its territorial integrity, political independence or security is under threat.
Meanwhile, Turkey's Prime Minister Tayyip Erdogan said his armed forces' rules of engagement have changed as a result of Friday's incident and they will respond to any violation on the Syrian border.
In an address to parliament, Mr Erdogan said Turkey would not engage in war-mongering, but the attack on the reconnaissance jet, which was deliberately targeted, would not be left unanswered.
