Iran's navy has begun an annual drill near the strategic Strait of Hormuz, its first major exercise since the inauguration of United States (US) President Donald Trump.

Iranian state television quoted navy chief Admiral Habibollah Sayyari on Sunday as saying the manoeuvre will cover an area of 2 million square kilometres in the Sea of Oman and the Indian Ocean near the strait.

Nearly a third of all oil traded by sea passes through the strait and it has been the scene of previous confrontations between the US and Iran.

But the drill does not involve Iran's elite Revolutionary Guard, a paramilitary force the US Navy often criticises for harassing its vessels.

The US Navy's 5th Fleet, based in Bahrain, did not immediately respond to a request for comment.