Syria's foreign minister has offered to help the US fight the Islamic State (IS) militant group, which has seized swathes of land in Iraq and Syria.
Walid Muallem said Syria was "the centre of the international coalition to fight Islamic State".
The US has already bombed IS fighters in Iraq and has hinted it would be willing to take action in Syria.
Western powers generally shun Syria's government, accusing it of carrying out atrocities in its three-year civil war.
But Mr Muallem warned that the US must co-ordinate with the Syrian government before launching any air strikes on its territory.
"Anything outside this is considered aggression," he said.
Mr Muallem's comments are one of the first public statements from the regime on IS.
More than 191,000 people have been killed in the Syrian conflict up to April, the UN says.
The conflict began as a popular uprising against the autocratic rule of President Bashar al-Assad.
The US and other Western powers have supported the opposition and repeatedly called for Mr Assad to resign.
But as the death toll has mounted, violent jihadists like IS have emerged as the most formidable rebel groups.
Syria, Iraq and Islamic State
Areas of IS activity
In a shock move, IS stormed and took over the city of Mosul in northern Iraq earlier this year.
IS, which originated in Iraq more than a decade ago, is believed to be one of the wealthiest militant groups in the world, through the takeover of banks and oil refineries and being backed by wealthy donors.
The brutality of its methods has alienated even other hardline jihadist groups.
Last week IS posted a video in which a British fighter beheaded an American journalist, James Foley, drawing condemnation from around the world.
In Syria, IS claims to be active throughout the country.
Its fighters have seized several military bases in northern Raqqa province, including an air base - the government's last foothold in the province - on Sunday.