Syria says chemical or biological weapons could be used if there is "external aggression"

(CBS/AP) BEIRUT, Lebanon - The Syrian regime acknowledged for the first time Monday that it possessed stockpiles of chemical and biological weapons and said it will only use them in case of a foreign attack and never internally against its own citizens.

Foreign Ministry spokesman Jihad Makdissi said the stockpiles are secure, in an apparent response to widespread international concerns that they could fall into the hands of the disparate bands of rebel forces fighting the government.

"No chemical or biological weapons will ever be used, and I repeat, will never be used, during the crisis in Syria no matter what the developments inside Syria," he said in conference broadcast on state TV. "All of these types of weapons are in storage and under security and the direct supervision of the Syrian armed forces and will never be used unless Syria is exposed to external aggression."

Syria is believed to have nerve agents as well as mustard gas, Scud missiles capable of delivering these lethal chemicals and a variety of advanced conventional arms, including anti-tank rockets and late-model portable anti-aircraft missiles.

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Makdissi also dismissed the latest overture from the Arab League, which offered Assad "safe exit" for him and his family if were to step down.

"This is wishful thinking," said Makdissi. "This is a blatant, immoral interference in the internal affairs of a sovereign state." It was the second offer for safe exit for Assad which the regime has flatly rejected in recent weeks.

Israel has said it fears that chaos following Assad's fall could allow the Jewish state's enemies to access Syria's chemical weapons, and has not ruled out military intervention to prevent this from happening.

A senior U.S. intelligence official said the Syrians have moved chemical weapons material from the northern end of the country, where the fighting was fiercest, apparently to both secure it, and to consolidate it, which U.S. officials considered a responsible step.

But there has also been a disturbing rise in activity at all the installations, so the U.S. intelligence community is intensifying its monitoring efforts to track the weapons and try to figure out whether the Syrians are trying to use them, the official said. A surge of satellite mapping was evidenced by the release of dozens of unclassified images of Syria on Friday.

Both officials spoke on condition of anonymity to discuss the still-evolving investigation.