The Iranian navy launched military exercises in the Gulf on Thursday in a display of the Islamic republic's "power and defence capability", the naval chief said.
"During these manoeuvres frigates equipped with missiles, warships, air-to-sea missiles and sea-to-air missiles are being used, as well as tactical reconnaissance submarines," Admiral Sajad Kushaki told state television.
The exercises, codenamed "Power," will run until March 30.
"If the United States starts a war against Iran, it won't be the US that finishes it," the ISNA news agency quoted a Revolutionary Guards navy general as saying.
"The Iranian people will not allow a single American soldier to set foot on their soil."
The manoeuvres come amid a continuing standoff between Tehran and world powers over Iran's controversial nuclear programme and as the UN Security Council mulls a new draft resolution to step up sanctions agreed December 23.
On Wednesday supreme leader Ayatollah Ali Khamenei warned in a nationally televised speech that Iran would do whatever it could to defend itself from force or the threat of force.
"If they want to use threats, to resort to force and violence, then without a doubt the people and the authorities will use all their capabilities to strike the enemies," he said.
Iran has staged several military exercises in recent months, displaying hardware including short-, medium- and long-range missiles.
On Friday state radio reported that the Iranian military has developed a new air defence system with a boosted ability to hit targets by firing two missiles simultaneously.
Western powers fear that Iran aims to produce nuclear weapons by enriching uranium, but Tehran insists its nuclear programme is for purely peaceful purposes.
Source: Agence France-Presse