On Monday, Trump said that Russia's failure to reach a negotiated settlement with Ukraine within 50 days would lead to his administration imposing a 100% tariff rate on Russian imports as well as what he called "secondary tariffs" on countries that have continued to do business with Moscow.

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.”

Russian President Vladimir Putin has sacrificed an estimated 1 million of his soldiers, killed and wounded, in a three-year campaign to crush Ukraine.