The Iranian navy will maintain regular missions in the Gulf, the Isna news agency reported on Wednesday after the United States warned mariners there to stay away from US warships.
"The naval units of the Islamic Republic of Iran in the [Arabian] Gulf and the Gulf of Oman will continue their regular missions in accordance with professional principles as in the past," Isna quoted an unnamed military official as saying.
The US warning to mariners to stay at least 100 metres from warships followed US President Donald Trump's threat last month to fire on any Iranian vessel that harasses its Navy.
"Armed vessels approaching within 100 meters of a US naval vessel may be interpreted as a threat," according to the text of the notice.
The Bahrain-based US Naval Forces Central Command said in a statement its notice was "designed to enhance safety, minimize ambiguity and reduce the risk of miscalculation".
A US official, speaking on condition of anonymity, said the new notice to mariners was not a change in the US military's rules of engagement.
The Pentagon has stated that Trump's threat was meant to underscore the Navy's right to self-defense.
It follows an incident last month in which 11 Iranian vessels came close to US Navy and Coast Guard ships in the Gulf in what the US military called "dangerous and provocative" behaviour. Tehran blamed its longtime adversary for the incident.
Friction between Tehran and Washington has risen since 2018, when Trump quit Iran's 2015 nuclear deal with six powers and reimposed sanctions on the country that crippled its economy.
The head of Iran's elite Revolutionary Guards last month said Tehran would destroy US warships if its security was threatened in the Gulf. Iran's clerical rulers consider the US military presence in the Middle East a threat to the Islamic Republic's security.
