Washington (AFP) - The Federal Aviation Administration has warned US airlines flying over the Gulf to exercise caution "due to heightened military activities and increased political tensions in the region."

The advisory, which also covers airspace over the Gulf of Oman, comes amid rising tensions between the US and Iran.

Increased tensions in the region "present an increasing inadvertent risk to US civil aviation operations due to the potential for miscalculation or mis-identification, said the FAA advisory released late Thursday.

The regulator also warned that aircraft flying in the area could encounter "inadvertent GPS interference and communications jamming, which could occur with little to no warning."

Washington has deployed an aircraft carrier group and B-52 bombers to the region against what it claims is an imminent threat from Tehran.

President Donald Trump's administration has also ordered non-essential diplomatic staff out of Iraq, citing threats from Iranian-backed Iraqi armed groups.

The White House however has sent mixed signals in recent days, amid multiple US media reports of infighting in Trump's cabinet over how hard to push Washington's arch foe.

According to US media reports, Trump's long-hawkish national security advisor John Bolton is pushing a hard line on Iran, but others in the administration are resisting.

The White House and Pentagon have been under pressure to demonstrate the reason for the huge buildup in forces and heightened rhetoric of the past two weeks.

US coalition partners in Iraq had suggested earlier this week that the threat level there had not risen significantly, and members of Congress demanded to see the information behind the administration's apparent preparation for possible conflict.