Iran regularly holds such military exercises but they are likely to heighten tensions, coming at a time of a deepening standoff between the West and Tehran over the country's controversial nuclear program.

"The massive maneuvers dubbed Velayat-89 will show (Iran's) defensive and deterrent naval power," Iranian Navy chief Adm. Habibollah Sayyari was quoted as saying by the official IRNA news agency. Submarine and air force units are also due to participate, he added.

Sayyari also confirmed a recent flyover by an Iranian surveillance jet and its close encounter with a US Navy aircraft carrier, the semi-official Fars news agency reported.

Iran "has the right to conduct routine surveillance flights," Fars quoted Sayyari as saying. He said the F-27 jet flew over the US vessel and "despite their objection, we persisted on our right" to carry out the surveillance.

Sayyari did not elaborate on the time and location of the flyover.

But a US military official said last week the US Navy had a close encounter in international waters of the Gulf of Oman. The official said the jet buzzed the USS Eisenhower, coming within about 1,000 meters of the ship on April 21. The official spoke on condition of anonymity because he was not authorized to speak publicly on the matter.

Iran's new war games are to start Wednesday, said IRNA.

Fars said the exercise would last for eight days and cover a span of about 97,000 square miles of Iranian territorial waters.

Iran's Revolutionary Guard held five-day maneuvers in late April in the Arabian Gulf and the Strait of Hormuz -- the waterway for around 40 percent of the world's oil and gas supplies.

The exercises are intended to show off the country's military might and act as a warning, should US or Israel consider a strike on Iranian nuclear facilities. The West suspects Iran's nuclear program is aimed at building an atomic bomb. Iran denies the charge, saying it's for peaceful purposes, such as power generation.

Meanwhile, Turkey will do all it can to avoid any military confrontation and sanctions on Iran, while ensuring Tehran is transparent about its nuclear program, its foreign minister said in a report published Tuesday.

"We will do everything possible to build trust between Iran and the United States and Iran and the West to avoid a military confrontation and possible sanctions," Ahmet Davutoglu was quoted as saying by Al-Hayat newspaper.

The Turkish minister, however, added "Iran must provide guarantees" that its nuclear program is for peaceful purposes and must be transparent with the International Atomic Energy Agency."

"We are working hard on easing tensions between Iran and the West, especially the United States. We are against the concept of sanctions not only against Iran, but against all our neighbors," he said.

The United States and other world powers are pressing for a fourth set of UN sanctions against Iran, accusing it of masking a weapons drive under the guise of what Tehran says is a purely civilian atomic program.

Turkey, a current non-permanent member of the UN Security Council, insists the dispute should be resolved through diplomatic means and has offered to act as a mediator.

In Tuesday's comments in the London-based daily, Davutoglu expressed hope of a solution but called for "more diplomatic efforts to engage with Iran in order to build trust between (all) sides."

Davutoglu said on a visit to Tehran last month that Turkey was ready to act as an intermediary between Iran and world powers in a bid to resolve the row over its nuclear program.

He was referring to a plan drafted by the UN nuclear watchdog last year that would have seen the major powers provide fuel for a Tehran research reactor in return for Iran shipping abroad most of its stocks of low-enriched uranium.