Syria's President Bashar al-Assad speaks to French journalists in Damascus, Syria, in this handout picture provided by SANA on January 9, 2017. [Photo/Agencies]

Assad, in comments to French media, also said his government was ready to negotiate on "everything" at peace talks his Russian allies hope to convene in Kazakhstan, including his own position within the framework of the Syrian constitution.

But he indicated any new constitution must be put to a referendum and it was up to Syrians to elect their president.

His opponents have insisted throughout nearly six years of war that he must leave power under any future peace deal. But since Russia joined the war on his side in late 2015, his government's position on the battlefield has strengthened dramatically, giving him greater leverage now than at any time since the war's earliest days.

The ceasefire which came into effect on Dec 30 aims to pave the way for the new peace talks which Russia hopes to convene with Turkish and Iranian support. But no date has been set for the talks and the warring sides have accused each other of truce violations.

The Moscow-led effort to revive diplomacy, without the participation of the United States, has emerged with Assad buoyed by the defeat of rebels in Aleppo, and as ties thaw between Russia and Turkey, long one of the rebels' main backers.

Ankara, now seemingly more worried by growing Kurdish sway in Syria than toppling Assad, supports the diplomatic push.