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.”

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.

President Donald Trump’s ultimatum to Russia to accept a peace deal in Ukraine within 50 days or face bruising sanctions on its energy exports has given the Kremlin extra time to pursue its summer offensive.