NATO chief Anders Fogh Rasmussen has said the option of carrying out a military strike against Syria must be maintained.
Speaking in Brussels on September 19, Rasmussen welcomed a U.S.-Russian agreement on the elimination of Syrian chemical weapons but said the threat of a military strike was still necessary.
"It remains to be seen exactly how the UN Security Council resolution will look, but I think it is essential for keeping momentum in the diplomatic and political process that the military option is still on the table," he said. "I think, irrespective of the outcome of the deliberations in the UN Security Council, the military option will still be on the table."
Rasmussen added that he has no doubt that the Syrian government was behind a chemical attack in the suburbs of Damascus last month that the United States says killed more than 1,400 people.
"I think it is quite clear that a variety of sources point to the Syrian regime as responsible for the horrendous chemical weapon attack on 21 August," he said. "The missiles were launched from areas controlled by the government. It doesn't make sense for the opposition to attack their own people with chemical weapons in areas they already control. And furthermore, we don't think that the opposition has at its disposal means to carry out a chemical-weapons attack of that scope and scale."
Meanwhile, President Bashar al-Assad has said his government will implement the plan to dispose of Syria's chemical weapons but noted it would take one year and $1 billion to complete the process.
In an interview with Fox News, Assad again denied his forces were behind the August 21 attack and criticized a UN report about the deaths.
"The whole story doesn't even hold together," he said. "It's not realistic. So, no, we didn't, in one word. We didn't use any chemical weapons in Ghouta because if you want to use it, you would harm your troops, you would have harmed the tens of thousands of civilians living in Damascus."
The UN report released on September 16 found "clear and convincing evidence" of a sarin nerve-gas attack on August 21, although the report did not assign blame for the chemical attack.
With reporting by Reuters and AP