In an interview with German public television ARD, al-Assad said the fighters “can return to their normal civil life” on condition that they hand in their weapons.
The Syrian regime has carried out several so-called “local ceasefires” with rebels, mainly in the central province of Homs and some areas near the capital Damascus.
These involved rebels handing over heavy weapons, and being allowed to leave with their families to other rebel-held areas if they so wished.
Referring to the US-Russian-brokered ceasefire that went into effect in Syria last Friday, the embattled president said: “We’ll do our part so that the whole (thing) works.”
The ceasefire was largely holding on Tuesday, despite accusations from the opposition that Russia and the Syrian government targeted rebel-held areas.
Al-Assad admitted that Syria was no longer “completely sovereign” and needed the backing of Russia, Iran and Lebanon – in an apparent reference to Shiite Islamist movement Hezbollah which has provided key backing to his overstretched forces.
But, he said, support from those countries would limit the spread of Islamist terror, not just to neighbouring countries, but to other regions.
“In the end they haven’t come to defend us, but to defend themselves,” he said.
Al-Assad welcomed Germany’s help in taking Syrian refugees but questioned whether it “wouldn’t be smarter and less expensive” to help Syrians to live in their own country.
Western powers too should join the fight against terrorism in Syria, al-Assad said.
He reiterated his country’s call on all the western world powers to join the fight against terrorism in Syria. Western countries have accused the Syrian leader of being partly responsible for the rise of extremism with his brutal crackdown on initially peaceful protests.