The US Transportation Department's Maritime Administration has issued a new warning about possible navigating concerns to the commercial shipping industry, due to a recent spate of attacks in the Arabian Gulf and Strait of Hormuz.
The advisory warns of potential Iranian interference and trouble reported with some tankers' GPS navigation.
The warning notes Iran could hinder navigation by interfering with GPS, or using other "communications jamming with little to no warning."
The federal agency said US commercial vessels should take certain precautions, including a review of security measures and ensuring Automatic Identification System is transmitting at all times.
Iran has attempted to disrupt civilian aircraft and ship navigation with GPS jammers on Iran-controlled Abu Musa Island in the Arabian Gulf, near the Strait of Hormuz, CNN reported.
The report said Iranian military boats have been "spoofing" boats' automatic identification system to pose as merchant ships.
The warning about possible navigating concerns came as President Donald Trump accused his French counterpart Emmanuel Macron of getting in the way of US policy and sending "mixed signals" to Iran.
"Iran is in serious financial trouble. They want desperately to talk to the US, but are given mixed signals from all of those purporting to represent us, including President Macron of France," Trump tweeted.
"I know Emmanuel means well, as do all others, but nobody speaks for the United States but the United States itself. No one is authorized in any way, shape, or form, to represent us!"
As the US-Iranian standoff deepens, tensions are soaring in the region, with drones downed, tankers seized by Tehran and mysterious attacks on ships in Gulf waters.
Washington has accused Iran of the attacks on ships.
In response, the US has been seeking to form a coalition whose mission-- dubbed Operation Sentinel -- it says is to guarantee freedom of navigation in the Gulf.
Britain, which already has warships on protection duty in the Gulf after a UK-flagged tanker was seized by Iranian Revolutionary Guards, has said it will join the planned operation.
Agence France Presse quoted Iran's defense minister as saying Thursday that the formation of the flotilla in the Gulf "will only increase insecurity in the region."
Reacting to reports of Israeli willingness to join the coalition, Amir Hatami said it would be "highly provocative and can have disastrous consequences for the region,"
Meanwhile, P&O Cruises said it has canceled cruises around Dubai and the Arabian Gulf over increased tensions.
The company said it has canceled its planned program in the region from October until at least March next year and all guests be issued a full refund.
