AP
Gen. Valery Gerasimov, left, and Gen. Charles Q. Brown, Jr.
CNN  — 

In their first ever call, Russia’s defense chief cautioned the top US general about a large-scale Russian military exercise in the eastern Mediterranean Sea, according to a US official, with tensions running high between the two countries over the escalating war in Ukraine.

The call between Chief of Russian General Staff Gen. Valery Gerasimov and US Chairman of the Joint Chiefs of Staff Gen. CQ Brown, which was initiated by Gerasimov, occurred November 27.

On Tuesday, the Russian Ministry of Defense announced that it had launched hypersonic missiles and cruise missiles as part of an exercise in the eastern Mediterranean Sea. Russian frigates, Admiral of the Soviet Union Fleet Gorshkov and Admiral Golovko, fired Tsirkon hypersonic missiles as part of the exercise, which included the Russian Navy and Aerospace Forces. The submarine Novorossiysk launched Kalibr cruise missiles at a naval target, according to the ministry.

The exercise involved more than 1,000 troops; 10 ships; and 24 aircraft, including MiG-31 fighter jets armed with Kinzhal hypersonic missiles, the ministry said.

Gerasimov did not explicitly mention the launch of hypersonic missiles in the call, according to the US official.

The US currently has two destroyers operating in the Mediterranean Sea, the USS Bulkeley and the USS Arleigh Burke, according to a spokesman for the Navy.

The New York Times was first to report on the call between Gerasimov and Brown.

This was the first call between Gerasimov and Brown since Brown became Joint Chiefs of Staff Chairman more than one year ago. An official readout of the discussion normally follows calls between Brown and his military counterparts, but the Russians asked not to do so in this case.

A spokesman for Brown confirmed the call happened but did not offer details, only saying, “The leaders discussed a number of global and regional security issues to include the ongoing conflict in Ukraine.”

Capt. Jereal Dorsey said in a statement, “At the request of Gen. Gerasimov, Gen. Brown agreed not to proactively announce the call.” There was no mention in the statement of the exercises in the Mediterranean Sea.

The US official said the two also discussed US concern over the deployment of North Korean troops to the battlefield and Russia’s use of an intermediate-range ballistic missile with multiple warheads in late-November. Another topic that came up in the call, the official said, was the US giving Ukraine permission to fire long-range ATACMS missiles into Russia.

US and Russia maintain deconfliction lines in certain combat zones to avoid unintentional encounters when the two militaries operate near each other. That line has been used recently in the Middle East to prevent any friction between US and Russian forces operating in Syria, the Pentagon said.

But since the start of the war in Ukraine nearly three years ago, the US and Russian military chiefs have rarely spoken, despite repeated outreach efforts by the US as the war began. Gerasimov spoke with former Joint Chiefs of Staff Chair Gen. Mark Milley in March 2023 after a Russian fighter jet struck and downed a US MQ-9 Reaper drone over the Black Sea.