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.

The president’s call for Ukraine to avoid hitting Moscow continued his pattern of swinging between pressure on both sides to end the war and underscored the uncertainties about his strategy.

Seemingly unfazed by President Donald Trump's 50-day ultimatum to end the fighting, Russia launched hundreds of drones and missile strike on six Ukrainian regions overnight, officials in the country said.

The skies over Moscow and St. Petersburg were filled with drones coming from Ukraine, days after President Trump told reporters Ukraine should not target Moscow

Two rounds of talks between Ukraine and Russia in Turkey this year yielded an agreement to exchange prisoners and soldiers' remains. But no date has yet been set for a new round of talks, and both sides remain far apart on the terms of any ceasefire.

As President Donald Trump hardens his position toward Moscow and seeks new ways to bring its war in Ukraine to an end, he says he isn’t looking to deliver Kyiv longer-range missiles that could strike targets deeper into Russia.

Donald Trump has privately encouraged Ukraine to step up deep strikes on Russian territory, even asking Volodymyr Zelenskyy whether he could strike Moscow if the US provided long-range weapons, according to people briefed on the discussions.

The United States was moving to get weapons to Ukraine quickly under President Donald Trump's plan for Europe to buy arms, and was weighing selling Patriot air defence systems from its own stocks, Washington's envoy to NATO said Thursday.