The UN monitoring mission to Syria is doomed to fail because President Bashar al-Assad will never comply with a ceasefire, the top rebel military leader was quoted on Thursday as saying.
General Mustafa al-Sheikh told pan-Arab daily Asharq al-Awsat there are only two possible solutions to ongoing violence.
One would be for the UN Security Council to put in place "mechanisms to make the regime fall" and the other would be military intervention.
As for a political solution, Sheikh said he believes Assad would not comply with UN-Arab League envoy Kofi Annan's plan for Syria because "a ceasefire would imply the fall of the regime."
Were regime forces to comply with the ceasefire and allow peaceful protest, Sheikh said, "millions of Syrians would take to the streets."
"The regime's nature is based on its security mentality" and "is built on oppression," the army defector and head of the Free Syrian Army's military council told the London-based newspaper.
He called for more international action, but said the Security Council will fail to act "so long as the Russian veto remains."
Russia, a long-time ally of Syria, and China have twice used their veto powers as permanent Security Council members to block tough resolutions on Syria.
As an alternative to UN-backed military action, Sheikh added that he had proposed "an air strike by the Friends of Syria group" during their last meeting in early April.
A putative UN-brokered ceasefire came into effect on April 12, and up to 300 unarmed UN observers are expected to arrive to monitor it.
An advance team, set to number 30 by the end of the week, is already on the ground.
In spite of his scepticism of the UN monitoring team's effectiveness, Sheikh said "we want Annan's plan to succeed," adding that he had instructed rebel fighters to "exercise restraint."
But the Britain-based Syrian Observatory for Human Rights has said regime forces have continued to kill scores in multiple locations, including Hama, central Syria, and Douma, in the Damascus region.
The Syrian authorities frequently blame "armed terrorist groups" for violence.
Opposition activists blame regime forces for killings. In recent days, more than 100 people in the central city of Hama have been killed, according to the Syrian National Council, the main opposition group.
On Tuesday, former UN chief Annan told Security Council that he was "concerned" about violence surging after members of the advance team visit individual cities.
The unrest began as a popular revolt against Assad's regime, but has turned into an insurgency that many fear could lead to all-out civil war.
More than 9,000 people have died since the revolt broke out in March 2011, according to the United Nations.