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

U.S. President Donald Trump's decision to ramp up arms shipments to Ukraine is a signal to Kyiv to abandon peace efforts, Russia said on Thursday, vowing it would not accept the "blackmail" of Washington's new sanctions ultimatum.

Russia launched four missiles and 136 drones into Ukraine overnight into Monday morning, according to Ukraine's air force.