And he's called on Western countries, which have carried out air strikes on IS in Syria along with Gulf allies since September 2014, to join forces saying they'll achieve results much faster together.
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In an interview broadcast by Iranian state television he said the alliance between Russia, Syria, Iraq and Iran must succeed or else the whole region will be destroyed.
In an extract of Assad's interview posted on Twitter, he said the chances of success for the coalition are great, but warned Syria's allies will pay a high price.
Russia on Wednesday launched air strikes in Syria in a move Moscow insists is aimed at fighting the Islamic State group, but opponents including the United States claim Russian bombing raids are mainly targeting Western-backed moderate opponents of Assad.
Russian raids against what Moscow says are Islamic State group targets took place for a fifth day yesterday, despite accusations in the West that the strikes are mainly targeting moderate opponents of the regime.
Assad said in an interview broadcast by Iranian state television the alliance between Russia, Syria, Iraq and Iran must succeed or else the whole region will be destroyed.
Western and Gulf countries insist Assad must step down after presiding over more than four years of a civil war that has killed more than 240,000 people.
