News - Middle East: The United States says it is "concerned" that Russians "may use chemical weapons in Ukraine," ratcheting up its propaganda offensive against Moscow over the Ukraine crisis.

In an interview on Sunday, US ambassador to the United Nations Linda Thomas-Greenfield vowed an aggressive response if Russia's military uses chemical weapons in Ukraine, days after Moscow revealed that the Pentagon financed a biological weapons research program in the former Soviet republic. .

“We are concerned that they may use chemical weapons in Ukraine. We've been clear if they escalate to this level, we will respond aggressively to what they're doing,” Thomas-Greenfield told host Jake Tapper on CNN's "State of the Union".

“Jake, as you know, that Russian came into the Security Council on Friday with the spurious accusations that the U.S. was supporting Ukraine's chemical weapons programs,” Thomas-Greenfield added.  “And I'm not going to give that any more amplification here. What we see happening is, again, this is a false flag effort by the Russians.”

“You've seen the consequences so far of our actions against Russia and against [Russian President Vladimir] Putin and they are feeling those consequences and they will feel more if they take this unfortunate….decision to use chemical weapons,” Thomas-Greenfield stated.