"Britain has been helping get arms to the Kurds and we are prepared to do more. We are considering actively whether to give them arms ourselves and whether we can do more directly to train Kurdish militia," the prime minister told ITV television.

The Royal Air Force has been transporting ammunition supplied by allies and British non-lethal equipment to the regional authority in Irbil, including 10 tons of British body armor overnight Wednesday.

But London is moving closer to directly arming the Kurds and providing them with training following the increased threat posed by ISIL militants who have seized territories across Iraq and Syria.

The group released a video this week showing the beheading of a second US journalist and threatening the life of a British captive, prompting London to warn it would look at "every option" to protect the hostage.

Asked if Britain would join the US in airstrikes on ISIL forces, Cameron said on the sidelines of the NATO summit in Newport, "I'm certainly not ruling anything out and I will always act in the British national interest."

Any decision to arm the Kurds would have to be done with the agreement of the Iraqi government in Baghdad, officials say.

The prime minister last month appointed Lt. Gen. Simon Mayall, a government military advisor, as special envoy to Iraq and sent him to the region to discuss how to deal with the threat of ISIL.

On Sunday, Germany announced it would be sending arms to Iraqi Kurds, breaking with a post-war policy of refusing to send weapons into conflict zones.

SHI/SHI