Beirut, June 15 (Reuters): The US said today it would keep F-16 fighters and Patriot missiles in Jordan at Amman’s request, and Russia bristled at the possibility they could be used to enforce a no-fly zone inside Syria.

Washington, which has long called for President Bashar al-Assad to step down, pledged military support to Syrian rebels this week, citing what it said was the Syrian military’s use of chemical weapons — an allegation Damascus has denied.

Defence secretary Chuck Hagel has approved a Jordanian request for American F-16s and Patriot missiles to remain in the western-backed kingdom after a joint military exercise there next week, a Pentagon spokesman said.

Western diplomats said yesterday Washington was considering a limited no-fly zone over parts of Syria, but the White House noted later that it would be far harder and costlier to set up one up there than it was in Libya. Russia, an ally of Damascus, said any attempt to impose a no-fly zone using F-16s and Patriots from Jordan would be illegal.