British Foreign Secretary, William Hague, said the United Kingdom and the United States have seen evidence that Syria is preparing to use chemical weapons.
Mr. Hague told the BBC there was “enough evidence to know that they need a warning.”
The foreign secretary did not give details, as he said the evidence had come from “intelligence sources.”
A Syrian official insisted last week that it would “never, under any circumstances” use such weapons.
That statement followed a warning on Monday from U.S President Barack Obama that there would be consequences if Syrian President Bashar al-Assad used chemical weapons against his people.
Mr. Hague told the BBC: “The president of the United States warned of serious consequences and he means it.”
Speaking at a security conference in Bahrain, he said he could understand why the public might be sceptical after the blunders made over Iraq’s alleged weapons of mass destruction 10 years ago.
Separately, western military sources in the Gulf have told the BBC that Syria’s chemical weapons are concentrated at five airbases and are being closely watched.
UK, U.S Have Evidence Of Syria’s Chemical Arms Plans