The Biden administration on Thursday accused Moscow of planning a staged mass casualty event on Russia by Ukraine, in order to justify a further Russian invasion of its former Soviet neighbor.State Department spokesperson Ned Price said that the intelligence had been newly declassified and presented to the press corps in the hopes that its publication would deter Russia from following through on the planned false-flag operation."The United States has information that Russia is planning to stage fabricated attacks by Ukrainian military or intelligence forces as a pretext for a further invasion of Ukraine," Price said in a Thursday briefing to reporters."One possible option that the Russians are considering and which we made public today involves the production of a propaganda video — a video with graphic scenes of false explosions, depicting corpses, crisis actors pretending to be mourners and images of destroyed locations or military equipment, entirely fabricated by Russian intelligence."Price said that disinformation campaigns like this are a favorite tactic of Moscow. He accused Russia of working on a video, not having had produced one.News of a possible false-flag operation by Russia comes after months of escalating tensions on Ukraine's eastern border.This week, the White House authorized the temporary relocation of some 3,000 troops closer to Ukraine after Russian President Vladimir Putin positioned a large military force along the Russia-Ukraine border.The U.S. already has some 60,000 troops based in Europe, but Russia has positioned about 127,000 troops near its border with Ukraine, former Ukrainian Defense Minister Andriy Zagorodnyuk told NPR last month.Speaking to reporters on Thursday, Price said that the false-flag attack is one of a number of potential tactics the U.S. has uncovered about Russia's Ukraine strategy."The production of this propaganda video is one of a number of options that the Russian government is developing as a fake pretext to initiate and potentially justify military aggression against Ukraine," Price said."We don't know if Russia will necessarily use this or another option in coming days. We are publicizing it now, however, in order to lay bare the extent of Russia's destabilizing actions towards Ukraine and to dissuade Russia from continuing this dangerous campaign and ultimately launching a military attack."Price did not outline what evidence the U.S. has to support its accusation against Russia, and his use of terms like "false flag" and "crisis actors" — popularized among civilians by fringe conspiracy theorists like radio host Alex Jones — bristled some in the press corps, who pressed the administration to provide evidence of its claims.Particularly, Associated Press reporter Matt Lee pressed Price several times, asking what proof the U.S. has to back up its claim. The American public, Lee said, shouldn't be expected to rely on the administration's word absent of material proof.Price responded: "If you doubt the credibility of the U.S. government, of the British government, of other governments and want to, you know, find solace in information that the Russians are putting out, that is for you to do."Price said that it is the standard procedure of the State Department to protect sensitive intelligence sources and methods and that the department declassifies information "only when we're confident in that information."The U.K., which accused Russia of similar tactics last month, backed the U.S. claim. "This is clear and shocking evidence of Russia's unprovoked aggression and underhand activity to destabilize Ukraine," U.K. Foreign Secretary Liz Truss said in a news release. "The UK and our allies will continue to expose Russian subterfuge and propaganda and call it out for what it is. The only way forward is for Russia to deescalate, desist and commit to a diplomatic pathway."President Biden has said he has been in communication with Putin and has made the United States' position clear: If Russia invades Ukraine, there will be consequences. Putin, Biden has said, has "never seen sanctions like the ones I promise will be imposed if he moves." And Biden vowed that it would be a "disaster for Russia" if the country invaded.The White House said last month: "If any Russian military forces move across the Ukrainian border, that's a renewed invasion, and it will be met with a swift, severe, and united response from the United States and our allies."The White House noted at the time Russia's frequent deployment of "aggression short of military action," like the false-flag operation the U.S. says that Russia is now considering. Copyright 2022 NPR. To see more, visit https://www.npr.org.