The White House said Tuesday that NATO would not provide Patriot missile batteries to protect rebel strongholds in Syria, following a request from opposition chief Ahmed Moaz al-Khatib.

Khatib asked for an extension of the umbrella provided by Patriot positions on the Turkish border designed to intercept any missiles fired from the Syrian side, as he took his seat at the Arab League summit in Doha.

"We are aware of the request," White House spoksman Jay Carney said.

"At this time, NATO does not intend to intervene militarily in Syria," Carney said.

"I think that a Patriot missile battery would follow the definition of military assistance," Carney said, adding that Patriot anti-missile batteries in Turkey were for self-defense only.

Carney added however that the White House was constantly reviewing its policies in Syria, which have seen Washington give hundreds of millions of dollars in humanitarian aid but stop short of providing "lethal" military help.

Syrian National Coalition leader Khatib said in Doha that he had asked US Secretary of State John Kerry to extend the Patriot missile protection into northern Syria, and that Kerry had "promised to look into the matter."

"We are still awaiting a decision from NATO on this matter," Khatib said.

A top State Department official was also cool to Khatib's demand for the Syrian opposition coalition, which he heads, to take up Syria's seat at the United Nations, saying that would be up to the UN.

"We recognize the Syrian Opposition Coalition as the legitimate representative of the Syrian people," Ventrell told reporters. "But in terms of recognition as a government, we're not there yet," he stressed.