"We will do our part so that the whole thing works," he told German public broadcaster ARD in an interview, referring to a three-day-old truce drawn up by Russia and the United States.
"We have refrained ourselves from retaliating in order to give (a) chance for the agreement to survive. That's what we can do, but at the end everything has a limit. It depends on the other side," he added.
Describing the truce as a "glimmer of hope", the president also offered an amnesty to opposition fighters if they agree to disarm.
"Just ... give up your armament, whether you want to join the political process or (are) not interested about the political process, you don't have any political agenda, it doesn't matter."
"The most important thing for me, legally and constitutionally, ... (is) that you're not allowed, as a citizen, to hold machine guns and hurt people or properties. This is the only thing that we ask. We don't ask for anything. As I said, we give them full amnesty," he said, as reported by AFP.
While describing the situation in his country as a "humanitarian catastrophe", Assad denied that his troops were cutting off food and medical supplies from rebel-held cities.
"How could we prevent them from having food while we cannot prevent them from having armaments?" he argued.