Decades-old tensions between Tehran and its arch enemy Washington have escalated since 2018, when US President Donald Trump withdrew from the Iran nuclear deal.

"The Islamic Republic of Iran has never been and will never be a source of tension or conflict in the region," the country's armed forces said in a statement carried by state media.

"But it will always defend its territorial integrity with promptness, tenacity and force," said the statement.

"It is clear that any adventurism, harassment or provocation will be met with a firm reaction from the Iranian armed forces, whose aggressors, especially the United States, will suffer the consequences," it added.

The Iranian armed forces also "strongly warned" the United States "and its satellite states" against the temptation to create "tensions... in the Gulf of Oman and the Persian Gulf".

The statement comes after an incident in Gulf waters on April 15 for which each side blamed the other.

"The Islamic Republic of Iran is keeping a close watch on the Americans and is monitoring their activities, but it will never trigger conflict or cause tension in the region," Iranian President Hassan Rouhani said on Sunday, according to a statement from his office.

Iran sees itself as the guardian of the Gulf and considers the American presence in the region as the source of all its ills.