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.”

Amid escalating tensions, former Russian President and current Security Council Deputy Chair Dmitry Medvedev fired back, calling US President Donald Trump's tariff warning a 'theatrical ultimatum' and claiming 'Russia doesn’t care.

Russia’s ex-president dismissed Trump’s 100 per cent tariff threat as a “theatrical ultimatum”, while the Kremlin said it was “very serious”, needing Putin’s analysis.