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.

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.

In response to the escalating threat, President Trump confirmed that the U.S. will send additional Patriot air defense missiles to Ukraine. He noted that the European Union would finance the purchase of what he described as "various pieces of very sophisticated" U.S. weaponry.