The U.S. has obtained intelligence indicating that the Russian government developed a plan to stage a false attack that would depict the Ukrainian military or its intelligence forces assaulting Russian territory to help establish a pretext for military action against Ukraine, a senior Biden administration official said Thursday.

The scheme included production of a graphic propaganda video that would show staged explosions and would use corpses and actors depicting grieving mourners, according to the official.

The news was first reported by The Washington Post. Pentagon spokesperson John Kirby confirmed the reports later Thursday at a briefing.

Kirby says the Pentagon has discussed such false flag operations before, and that a fabricating a pretext for invasion is "right out of [Russia's] playbook."

"One option is the Russian government, we think, is planning to stage a fake attack by Ukrainian military or intelligence forces against Russian sovereign territory or against Russian-speaking people, to therefore justify their action," Kirby said at a briefing Thursday. "As part of this fake attack, we believe Russia would produce a very graphic propaganda video, which would include corpses and actors that would depicting mourners and images of destroyed locations, as well as military equpment, at the hands of Ukraine or the west even to the point where some of this equipment would be made to look like it was Western-supplied to Ukraine equipment."

"And this is just one example we can talk about today," Kirby said. "We've seen these kinds of activities by the Russians in the past, and we believe its important, when we see it like this, we should call it out."

The plan, which was revealed in declassified intelligence shared with Ukrainian officials and European allies in recent days, is the latest allegation by the U.S. and Britain that Russia is plotting to use a false pretext to go to war against Ukraine.

The White House in December accused Russia of developing a "false-flag" operation to create pretext for an invasion. Britain recently named specific Ukrainians it accused of having ties to Russian intelligence officers plotting to overthrow Ukrainian President Volodymyr Zelenskyy. The U.S. also released a map of Russian military positions and detailed how officials believe Russia will try to attack Ukraine with as many as 175,000 troops.

The U.S. has not provided detailed information backing up the intelligence findings. The official said that the Biden administration is making a concerted effort to publicize the intelligence in the hopes that it dissuades Russia from moving forward with an invasion of Ukraine.

The White House is concerned that the video, if released, could provide Putin "the spark" they believe he is looking for to credibly put military action in motion.

The U.S. unveiled the the intelligence as Turkish President Recep Tayyip Erdogan offered to mediate talks between Russia and Ukraine and NATO warned that Moscow's military buildup continues, with more troops and military equipment deployed to neighboring Belarus than at any time in the last 30 years.

Erdogan, who has close but sometimes difficult ties with Russian President Vladimir Putin, said Thursday that Turkey was "prepared to undertake its part in order to end the crisis between two friendly nations that are its neighbors in the Black Sea."

"I have stressed that we would be happy to host a summit meeting at a leadership level or technical level talks," Erdogan said after about three hours of talks with Ukrainian President Volodymyr Zelenskyy. "Instead of fueling the fire, we act with the logical aim of reducing the tensions."

Russia has amassed more than 100,000 troops near Ukraine's northern and eastern borders, raising concern that Moscow might invade again, as it did in 2014. The troop presence and uncertainty have unnerved Ukrainians and hurt the country's economy. Russian officials deny that an invasion is planned.

Erdogan underlined Turkey's commitment to Ukraine's territorial integrity and sovereignty. Turkey and Ukraine also signed eight agreements during the meeting, including a free trade pact, according to Turkey's state-run Anadolu Agency.

Zelenskyy welcomed Erdogan's offer and thanked him for his "firm and consistent" support.

The crisis has put Turkey in a fix, leaving it in a position where it has to balance its growing partnership with Ukraine with its difficult relations with Moscow.

Ankara, which has historic ties to Ukraine and ethnic bonds with its Crimean Tatar community, strongly opposed Russia's 2014 annexation of Crimea. Recently, it sold armed drones to Ukraine, which were used against pro-Russia separatists in the Donbas region, a move that angered Moscow.

At the same time, Turkey would be reluctant to joint in any sanctions against Russia. With a struggling economy, the country has pinned its hopes on tourism revenue, especially from visitors from Russia. It also relies on Russia for much of its natural gas needs.

At NATO headquarters earlier, Secretary-General Jens Stoltenberg warned that Russian troop numbers in Belarus are likely to climb to 30,000, with the backing of special forces, advanced fighter jets, Iskander short-range ballistic missiles and S-400 ground-to-air missile defense systems.

"Over the last days, we have seen a significant movement of Russian military forces into Belarus. This is the biggest Russian deployment there since the Cold War," Stoltenberg told reporters.

Russian Defense Minister Sergei Shoigu was in Minsk on Thursday, checking on preparations for major Russia-Belarus war games scheduled for Feb. 10 to Feb. 20. Shoigu met with Belarusian President Alexander Lukashenko. Speaking about the drills, Lukashenko said the goal was "to reinforce the border with Ukraine."

At the same time, Ukraine's defense minister sought again to project calm, saying the probability of an invasion was "low," and he welcomed a change by U.S. officials, who have stopped using the term "imminent" when describing the risk of a Russian attack.

Oleksii Reznikov said "the threat exists, the risks exist, but they have existed since 2014, ever since Russia has become an aggressor." He said "there are no grounds for panic, fear, flight or the packing of bags." The minister put the number of Russian troops near Ukraine at 115,000.

Still, Stoltenberg renewed his call for Russia to "de-escalate," and repeated warnings from the West that "any further Russian aggression would have severe consequences and carry a heavy price."

NATO has no intention of deploying troops to Ukraine should Russia invade, but it has begun to reinforce the defenses of nearby member countries — notably Estonia, Latvia, Lithuania and Poland. The 30-nation military alliance also plans to beef up its defenses in the Black Sea region near Bulgaria and Romania.

Stoltenberg also embraced President Joe Biden's decision on Wednesday to send 2,000 U.S.-based troops to Poland and Germany and to shift 1,000 more from Germany to Romania, demonstrating to both allies and foes Washington's commitment to NATO's eastern flank.

"We are committed to finding a political solution to the crisis, but we have to be prepared for the worst," Stoltenberg said, and he appreciated other recent offers of troops and equipment from several allies. Russia objects to the troop move and has described it as "destructive."

In Helsinki, Finnish leaders held talks with European Commission President Ursula von der Leyen about a letter that Russian Foreign Minister Sergey Lavrov sent to several countries on the "indivisibility of security" in Europe.

Lavrov argues that the U.S. and NATO misunderstand the concept — which essentially means that the security of one European country is linked to the security of them all — and he has demanded replies from countries that signed a key security document encompassing it to clarify the issue.

Finnish Prime Minister Sanna Marin said there was no "big news" in the letter but that it warranted a reply. Von der Leyen said the commission, the EU's executive branch, will coordinate a response, even though Lavrov insisted that only countries and not organizations should answer.