Gulf Arab states are cooperating on regional missile defence and hope to announce the results soon, a Bahraini officer said on Wednesday, suggesting progress in long-stalled efforts to create a cross-border approach to counter Iran's growing missile capabilities.

Past attempts have stumbled due to strains within the six-nation Gulf Cooperation Council (GCC) but US and Gulf officials say the time has come to push ahead as Arab nations start to mount more joint military missions.

Gulf Arab countries also worry that the lifting of sanctions against Iran, their long time adversary, could revive Iran's economy and enable it to acquire more accurate and reliable missiles.

Hamad Al Khalifah, commander of the Royal Bahraini Air Force, said on the sidelines of an air force conference that a GCC committee was working in a cooperative effort to build joint missile defence.

"We have started, and hopefully it (the result) will be announced soon," he said in answer to questions, without elaborating.

Iran conducted a precision-guided ballistic missile test capable of delivering a nuclear warhead violating a United Nations ban last October.

US President Barack Obama said the test was a violation of Iran's "international obligations" and a result Washington imposed sanctions on 11 companies and individuals for supplying Iran's ballistic missile program.

Obama and GCC countries underscored a commitment to build the defence system at a summit in May 2015, as Washington moved to assuage Gulf allies' concerns about a more powerful Iran.

A joint statement following the summit said that the GCC states were committed to developing a ballistic missile defence capability, including an early warning system, with US technical help. Washington pledged to fast-track arms transfers to the GCC states and to send a team to the region in the coming weeks to discuss the details. – Reuters