Officials with the Biden administration on Sunday again claimed that Russia may attack Ukraine soon and the Kremlin might create a surprise pretext for an invasion, although Moscow denied the allegations. “We cannot perfectly predict the day, but we have now been saying for some time that we are in the window, and an invasion could begin—a major military action could begin—by Russia in Ukraine any day now,” White House National Security Adviser Jake Sullivan told CNN on Sunday, repeating a claim that he made during a news conference on Friday. Sullivan said Moscow may consider attacking its Eastern European neighbor before Feb. 20, or before the end of the Winter Olympics in Beijing. He did not provide a specific piece of evidence to corroborate his claim. To make his argument for Moscow’s plans of an imminent invasion, Sullivan said that Russia has “built up” and “maneuvered” its forces in a …