Russian Security Council Secretary-General Nikolai Patrushev said Russia would try to find the wreckage of the U.S. drone that Washington accused Moscow of causing the crash in the Black Sea off Ukraine on Tuesday, while a U.S. official spoke of steps his country had taken to "protect its property," without elaborating.

Patrushev said in an interview with Russian television on Wednesday that the incident of the US march - an MQ-9 Reaper - showed Washington's direct involvement in the conflict in Ukraine.

He said Russia would try to get to the wreckage of the plane, but said he did not know if those attempts would succeed.

Russian Foreign Intelligence Director Sergei Naryshkin said Russia had the technical capabilities to pull the wreckage of the U.S. drone from the Black Sea.

Moscow warned on Tuesday against any "hostile" U.S. sorties following the incident, which escalated tensions between Russia and Western powers.

Moscow has denied that a Russian Su-27 fighter jet broke the U.S. drone's propeller, with Washington saying the fighter hit the drone while flying over the Black Sea on a "routine mission."

Russian Ambassador to the United States Anatoly Antonov said on Wednesday: "We assume that the United States will refrain from spreading additional speculation through the media and will put an end to overflights near the Russian border."

"We consider any move using US weapons an open act of hostility," he wrote on Telegram.

The Russian Defense Ministry said on Tuesday it had rushed to deploy its fighter jets after spotting the U.S. drone over the Black Sea, denying that it had been shot down or that its fighter jets had come into contact with it in any way.

The Reaper march is armed in some of its missions with missiles or laser-guided bombs (Reuters)

Washington reiterates its accusations

For its part, the Pentagon noted that his career was on a routine mission when it was intercepted in a "reckless and unprofessional" manner, and declined to say whether the march carried any missiles.

White House National Security Council spokesman John Kirby later said: "We of course refute Russian denials."

He said the United States was trying to avoid the march falling "into the wrong hands."

Kirby told CNN, "We've taken steps to protect our property particularly in connection with that march."

The US spokesman said Russia usually carries out interception operations over the Black Sea, but this time the operation "was remarkable because of its degree of unsafety and unprofessionalism, and how reckless it was."

Meanwhile, The New York Times quoted a U.S. military official as saying that the march that fell in the Black Sea took off from Romania on a scheduled reconnaissance mission.

The United States uses MQ-9 Reaper drones for reconnaissance purposes as well as for strikes. It has long been flying over the Black Sea to monitor Russian naval forces.

According to the US Air Force, this drone can be equipped with Hellfire missiles and "smart" laser-guided bombs, and can fly more than 1770 kilometers and at an altitude of up to 15,<> meters.