The United States military has deployed two extra Patriot missile batteries to Saudi Arabia and Qatar to protect critical oil and gas facilities.

One battery was sent to Saudi Arabia to guard a major oil installation. The second went to Qatar to defend a natural gas facility, according to an Axios report.

The report, citing two US officials and a regional source, said the move follows fears that Tehran could target Gulf energy assets if Washington restarts major strikes against Iran.

In early August, the leaders of Saudi Arabia and Qatar urged President Donald Trump not to launch a major attack on Iranian energy infrastructure. They feared Iranian retaliation against their own facilities.

The deployments coincide with a wider American military buildup in the Middle East. The USS Theodore Roosevelt carrier strike group is heading to the region and is expected around mid-November.

The US has reportedly warned that American air defence stockpiles are under strain. Patriot interceptor reserves have fallen sharply after heavy use in the war with Iran.