President Joe Biden has warned, pushing back on Russian claims that it has lessened its troops along the border of Ukraine as false, that Russia may engage in a false-flag operation as use that to justify their entry into Ukrainian territory. Before boarding Marine One on Thursday, Biden told reporters that the United States predicts the threat of a Russian invasion of Ukraine is “very high” and that his sense is it will happen “in the next several days.” “They have not moved any of their troops out. They’ve moved more troops in, number one. Number two, we have reason to believe that they are engaged in a false-flag operation to have an excuse to go in,” Biden said. The Pentagon last month had also warned that it was predicting Russia could use a false flag operation as pretext for invading Ukraine. Later Thursday morning aboard Air Force One, White House …