The comments were made after the United States said it was considering extending the fight against militants from the so-called Islamic State of Iraq and the Levant (ISIL) terrorist group into Syrian territory.
Moallem, speaking at a news conference broadcast on Syrian state TV on Monday, stressed airstrikes alone would not be adequate to deal with ISIL, which has taken control of large areas of Syria and neighboring Iraq.
Moallem also said neighboring states needed to exchange intelligence with Syria.
Asked if Syria was ready to cooperate with the United States and Britain, he said: "They are welcome."
Moallem also condemned the killing of US journalist James Foley, who was executed by ISIL.
RA/NJF