It was the first call between Austin and Defense Minister Sergei Shoigu since October. And Gen. Mark Milley, chairman of the Joint Chiefs of Staff, had a similar call with his Russian counterpart, Gen. Valery Gerasimov, the chief of the General Staff of the Russian armed forces.

"We take any potential for escalation very seriously. And that's why I believe it's important to keep the lines of communication open," Austin said at a Pentagon press briefing. "I think it's really key that we're able to pick up the phone and engage each other. And I think that that will help to prevent miscalculation going forward."

The U.S. military said it ditched the Air Force MQ-9 Reaper in the sea after a Russian fighter jet poured fuel on the surveillance drone and then struck its propeller while it was flying in international airspace. Russia has denied that it caused the accident. The U.S. has said it was working on declassifying surveillance footage from the drone that would show Tuesday's crash.?

The U.S. also released?a minute-long declassified video footage of an armed Russian Su-27 aircraft conducting what it called "an unsafe/unprofessional intercept" of a US Air Force MQ-9 in international airspace over the Black Sea on March 14.?

US-Russia feud

Russia and the United States ratcheted up their confrontational rhetoric Wednesday over a US surveillance drone that encountered Russian warplanes and crashed near Ukraine's Crimean Peninsula, which the Kremlin has illegally annexed. At the same time, both countries pledged to try to avoid escalation.

The Kremlin said the incident proved again that Washington is directly involved in the fighting and added that Moscow would try to recover the drone's wreckage from the Black Sea. U.S. officials said the incident showed Russia's aggressive and risky behavior and pledged to continue their surveillance.

Russia has long voiced concern about U.S. surveillance flights near its borders, but Tuesday's incident signaled Moscow's increasing readiness to raise the ante as tensions soar between the two nuclear powers. It reflected the Kremlin's appetite for brinkmanship that could further destabilize the situation and lead to more direct confrontations.

All about the fighter jet-drone collission over Black Sea

A Russian fighter jet on Tuesday struck the propeller of a US surveillance drone over the Black Sea, causing American forces to bring down the unmanned aerial vehicle in international waters, the US military said, an incident that highlighted soaring US-Russian tensions over Moscow's war in Ukraine.

White House National Security spokesman John Kirby said US President Joe Biden was briefed on the incident by national security adviser Jake Sullivan. Kirby added that US State Department officials would be speaking directly with their Russian counterparts and “expressing our concerns over this unsafe and unprofessional intercept.”

Tuesday's incident appeared to mark the first time since the height of the Cold War that a US aircraft was brought down after being hit by a Russian warplane.

The US European Command said in a statement that two Russian Su-27 fighter jets “conducted an unsafe and unprofessional intercept” of a U.S. MQ-9 drone that was operating within international airspace over the Black Sea.

?It said one of the Russian fighters “struck the propeller of the MQ-9, causing U.S. forces to have to bring the MQ-9 down in international waters.” Prior to that, the Su-27s dumped fuel on and flew in front of the MQ-9 several times before the collision in “a reckless, environmentally unsound and unprofessional manner,” the US European Command said in a statement from Stuttgart, Germany

“This incident demonstrates a lack of competence in addition to being unsafe and unprofessional,” it added.

US Air Force Gen. James B Hecker, commander of US Air Forces Europe and Air Forces Africa, said that the MQ-9 aircraft was "conducting routine operations in international airspace when it was intercepted and hit by a Russian aircraft, resulting in a crash and complete loss of the MQ-9.” He added that “in fact, this unsafe and unprofessional act by the Russians nearly caused both aircraft to crash.”

There was no immediate reaction from Moscow, which has repeatedly voiced concern about U.S. intelligence flights close to the Crimean Peninsula, which Russia illegally annexed from Ukraine in 2014. The Kremlin has charged that by providing weapons to Ukraine and sharing intelligence information with Kyiv, the US and its allies have effectively become engaged in the conflict.

Kirby emphasized that the incident wouldn't deter the U.S. from continuing their missions in the area.

“if the message is that they want to deter or dissuade us from flying, and operating in international airspace, over the Black Sea, then that message will fail,” Kirby said, adding “that is not going to happen.”

“We're going to continue to fly and operate in international airspace over international waters,” he said. “The Black Sea belongs to no one nation.”

The U.S. European Command noted that Tuesday's incident followed a pattern of dangerous actions by Russian pilots while interacting with U.S. and Allied aircraft over international airspace, including over the Black Sea.?

“These aggressive actions by Russian aircrew are dangerous and could lead to miscalculation and unintended escalation,” it warned.

Gen. David Berger, commandant of the Marine Corps, said that this type of collision is his greatest concern, both in that area of Europe as well as in the Pacific.

“Probably my biggest worry both there and in the Pacific is an aggressive Russia or China pilot or vessel captain, or something gets too close, doesn't realize where they are, and causes a collision,” Berger said, in response to a question at a National Press Club event on Tuesday.

He said that whether an incident is intentional or not, it forces nation's leaders to try and sort it out quickly from afar.

(With AP inputs)