The United States will be a "natural ally" of Syria if President-elect Donald Trump has the "will" and the "ability" to "fight the terrorists", President Bashar al Assad has said.
In his first television interview since Mr Trump's election victory last week, Mr Assad said he would "definitely" cooperate with the billionaire tycoon if he was "genuine" in his support.
However Mr Assad added that he is "dubious" as to whether Mr Trump can "live up to his promises" in the battle against so-called Islamic State.
In an interview with RTP, Mr Assad said: "What about the countervailing forces within the administration, the mainstream media that were against him? How can he deal with it?
"That's why for us it's still dubious whether he can do or live up to his promises or not.
"That's why we are very cautious in judging him, especially as he wasn't in a political position before.
"We cannot tell anything about what he's going to do, but if, let's say if he is going to fight the terrorists, of course we are going to be ally, natural ally in that regard with the Russian, with the Iranian, with many other countries who wanted to defeat the terrorists."
Syrian state television said the Damascus government's air force took part in strikes against "terrorist strongholds" in Aleppo's Old City while Russia said it had struck Islamic State and former Nusra Front sites elsewhere in Syria.
The bombardment appeared to mark the end of a pause in strikes on targets inside the city declared by Syria's government and Russia on October 18.
The renewed violence in Aleppo will be closely followed in Washington where Mr Trump has signalled he intends to take a different approach to Syria from that of President Obama, who has backed some rebel groups.
Mr Trump and Russian President Vladimir Putin, whose approach in Syria has been praised by the US President-elect, and agreed to "combine efforts to tackle international terrorism and extremism", the Kremlin said.