Iran’s armed forces on Thursday began a large-scale military exercise in the southern waters of the country amid unprecedented escalation of tensions with the US.

The three-day military drill, dubbed Zulfiqar-99, involves Iran’s army, navy, air force and air defense force and many newly developed weapons.

The massive drill is being conducted over 2 million square kilometers (772,204 square miles) territory covering eastern waters of the Strait of Hormuz, the Sea of Oman, the Makran coast and the northern Indian Ocean with the theme “sustainable security under deterrent power.”

The drill kicked off Thursday morning with surface and subsurface vessels, air and naval flights, radar and missile systems under the command of Zulfiqar Army Base, sources said.

The objective of the drill is to test country’s offensive and defensive tactical plans to safeguard Iran’s territorial waters amid heightened tensions in the region.

Many incidents have been reported in the Persian Gulf region involving vessels of Iran and US in recent months, at times coming dangerously close to confrontation.

The two countries have regularly exchanged barbs since May 2018 when US President Donald Trump announced withdrawal from the Iran nuclear deal and reinstated sanctions.

Over the two years, Iran’s military drills have become a regular feature, which experts believe is a “show of power” to its adversaries.

The latest drill, according to Rear Admiral Habibollah Sayyari, deputy chief of Iran’s army, is to “boost the military readiness and capability in naval, aerial, ground and air defense fields.”

“Security in West Asia and its strategic waterways requires indigenization of security cooperation from all regional countries and preventing foreign presence in regional waters,” Sayyari said, in a veiled reference to the US vessels.

During the drill, Iran’s long-range drone Simorq will be tested in combat operations against mock enemy vessels apart from reconnaissance missions, he said.

Iran’s army has recently tested a large variety of newly developed missiles and weapons in massive military drills, including in July’s Great Prophet 14 drill in the Persian Gulf.

Sirous Amerian, a security analyst with focus on Middle East, told Anadolu Agency that these annual military drills have become “important” for Iran in recent times.

“It is a show of force and readiness at a time that they [Tehran] look weak,” he said, adding that the phase of “strategic patience” is over.