That included a Monday joint statement from Republican Sen. Lindsey Graham and Democratic Sen. Richard Blumenthal calling Trump’s threat of ramped-up economic penalties if Russia doesn’t cut a peace deal in next 50 days “a real executive hammer to drive the parties to the negotiating table.”

The Kremlin said on Tuesday that U.S. President Donald Trump's recent statements, including a threat of sanctions on buyers of Russian exports, are serious and require analysis.