Syria said yesterday it was willing to work with the international community, including the United States, to tackle "terrorism" but that any strikes on its territory must be coordinated with Damascus.
Foreign Minister Walid Muallem made the comments as the Islamic State jihadist group advances in Syria and neighbouring Iraq, where Washington is already carrying out air strikes.
"Syria is ready for cooperation and coordination at the regional and international level to fight terrorism and implement UN Security Council Resolution 2170," Muallem said.
Muallem said Syria was willing to work within international or regional coalitions as well as on bilateral terms.
He said Damascus was also prepared to work with the United States and Britain, both of which back Syrian rebels in their fight to overthrow President Bashar al-Assad.
"They are welcome," he said.
"We must feel that the cooperation is serious and not double standards. Any violation of Syria's sovereignty would be an act of aggression," he said.
Asked if Syria's air defences could shoot down US planes, he said: "That could happen if there was not prior coordination. We are proposing international cooperation and coordination to prevent" such a scenario. There would be "no justification" for strikes on Syrian territory "except in coordination with us to fight terrorism."
But US chairman of the Joint Chiefs of Staff General Martin Dempsey acknowledged last week that IS could not be defeated in Iraq alone.
"Can they be defeated without addressing that part of the organisation that resides in Syria? The answer is no," he said.
Muallem said even air strikes would be insufficient to wipe out the IS, which emerged from Al-Qaeda's former Iraqi affiliate but has since broken ranks with that group.
"We welcome every effort to fight Al-Nusra Front and the Islamic State, but the real question is: are air strikes enough to wipe them out? I don't think so," he said.
Any strikes would have to be accompanied by "the drying up for the sources of terrorism, particularly financing and arming, along with proper control of the border and intelligence sharing," he added.
The IS has advanced in Syria, taking territory from both armed opposition groups in northern Aleppo province and from the Syrian army in Raqa province, also in the north.