Even as Iran claims of escalating threats from Israel and the U.S, it is hastily adding new weapons to its armory.
Latest is an indigenously built submarine that is equipped with hi-tech weaponry including cruise missiles and other cutting-edge equipment.
According to reports, Iran's tensions with Saudi Arabia are also up.
The 527-tonne semi-heavy Fateh submarine was commissioned on Monday in the presence of Iranian President, Hassan Rouhani at the Persian Gulf.
The submarine carries torpedoes, naval mines, and cruise missiles. It can fire missiles from a submerged position at a depth of more than 200 meters and lay low for more than a month.
In a televised address Rouhani said the "Fateh Submarine is joining Iran's naval force" and added that Iran's deterrence is purely defensive.
According to an analyst, the launch of the submarine is a message to Washington, says an Al Jazeera report.
"The Fateh is entirely a homegrown submarine that is designed and developed by experts of the defense ministry and is equipped with the world's modern technologies," Defense Minister Amir Hatami said.
The latest submarine adds to Iran's existing fleet of three Russian-built Kilo-class attack submarines and a few midget submarines.
Iran is focussed on developing a domestic arms industry as international sanctions have affected its arms imports. In 2018, Iran released a domestically built destroyer with radar-evading properties.
Iranian Navy chief, Rear Admiral Hossein Khanzadi said the Fateh would carry out a major mission in the Oman Sea.
Iran calls U.S. sanctions as economic warfare
Meanwhile, president Rouhani called the U.S. sanctions on Iran as an "economic war" that is "more difficult than military war."
He was speaking at the inauguration of the last phase of the Persian Gulf Star refinery in the port city of Bandar Abbas.
The refinery's construction started in 2006, the year when the United Nations imposed economic sanctions on Iran for pursuing nuclear enrichment programs. The sprawling refinery has a vast capacity and can produce 400,000 barrels a day. It is expected to process 20 percent of Iran's daily capacity that is about 2.1 million barrels a day.
Rouhani lauded the completion of the new facility despite America's "imposing the harshest sanctions" on Iran.
Sanctions on Iran were eased in 2015 after Iran and world powers signed a nuclear deal on the condition that Iran will halt its nuclear program for 15 years.
However, the Trump administration walked out of the nuclear deal in 2018 and clamped fresh sanctions on Iran and targeted its oil sector.
"Our ultimate aim is to compel Iran to permanently abandon its well-documented outlaw activities and behave like a normal country," the U.S Secretary of State Mike Pompeo said.
But Iran says the U.S. breached international law by its pullout from the multilateral deal.
The article originally appeared in IBTimes US.