U.S. Secretary of State John Kerry says NATO must consider its role in the Syrian conflict, including how it will respond to any potential use of chemical weapons.
The top U.S. diplomat spoke Tuesday at a meeting of NATO foreign ministers in Brussels.
NATO Secretary-General Anders Fogh Rasmussen said the alliance is very concerned about the use of ballistic missiles in Syria and the possible use of chemical weapons.
Earlier Tuesday, a senior Israeli military intelligence analyst, Brigadier General Itai Brun, said Israel has evidence Syrian forces have used lethal chemical weapons against rebels several times in recent months. He said nerve gas is possibly among the weapons used.
Kerry said he spoke with Israeli Prime Minister Benjamin Netanyahu about the general's allegation, but that Netanyahu was not able to confirm it. Kerry also said whatever allegations are made must be fully investigated.
"I just think that the information I have at this point does not confirm it to me in a way that I would be comfortable commenting on it as a fact." said Kerry. "But obviously whatever allegations are made have to be thoroughly investigated, and it is appropriate to chase this one down and find out what's going on, no question about it."
Syria has rejected a request by U.N. Secretary-General Ban Ki-moon to allow inspectors into the country to investigate claims Syria is using chemical weapons.
Syria's government and rebels opposed to President Bashar al-Assad have traded accusations about the use of chemical weapons.
Rasmussen also said NATO will not intervene in the Syrian conflict despite the threat the violence poses to security on the alliance's southeastern border. He said, however, NATO cannot ignore the risks of a regional spillover with possible implications for allied security.
Earlier this year, the alliance deployed Patriot anti-missile batteries along member Turkey's border with Syria, after artillery fire hit several villages.
Shortly after Tuesday's meeting began, NATO condemned North Korea's nuclear weapons program and threatening rhetoric. The alliance said Pyongyang's actions violate U.N. Security Council resolutions and undermine regional stability.
Tuesday's talks marked the first time Kerry met with his NATO contemporaries since taking his current post in January. On Wednesday, he will host a meeting in Brussels with Afghan President Hamid Karzai and senior Pakistani officials.