Syrian President Bashar al-Assad says it would be "difficult" to implement an internationally backed truce in the war-torn country.
The deal, agreed by world powers in Munich last week, calls for a cessation of hostilities to start in a week in Syria.
But Assad poured cold water on the plan in televised comments in Damascus on February 15.
"They are saying they want a cease-fire in a week. Who is capable of gathering all the conditions and requirements in a week? No one," he said. "Practically, talking [about a cease-fire] is difficult."
Assad said any cease-fire did not mean each side had to stop using weapons and nobody was capable of securing the conditions for one within a week.
"Regarding a cease-fire, a halt to operations, if it happened, it doesn't mean that each party will stop using weapons," Assad said.
He also said any political transition in the country must be subject to the existing Syrian Constitution.