KYIV, Ukraine — Ukrainian President Volodymyr Zelenskyy urged supporters Saturday to speak out in defense of new U.S. sanctions against Russia, hours after President Donald Trump signed an executive order pausing a sweeping package of restrictions targeting the Russian economy.

The White House decision has further raised fears that Ukraine could be left exposed to Moscow’s escalating assaults with winter approaching.

Russian attacks overnight killed at least four people, including an ambulance driver, and wounded dozens, officials said. Ukrainian drones killed a woman in a Russian border region and disrupted flights at Moscow’s airports, according to Russian authorities.

In a statement on social media, Zelenskyy described Trump’s move to put sanctions on hold as unfortunate, but did not directly criticize the U.S. leader despite deepening tensions between Ukraine and Washington in recent days.

“A decision was unfortunately made in America to completely disregard the Lindsey Graham Act, which was supposed to impose truly effective pressure on Russia to bring this war to an end,” Zelenskyy wrote.

Later, in audio clips answering journalists’ questions, Zelenskyy thanked Democrats and Republicans who backed the legislation and praised its bipartisan support. He said blocking it would encourage Russia to continue killing and do nothing to bring the war to an end.

He also added that limiting Ukraine’s ability to retaliate against Russian attacks would not bring peace.

“Nevertheless, we very much hope — and I personally hope — that the president of the United States of America will do everything possible to make Putin stop the killing, stop the attacks on our energy infrastructure, and end this war,” he said.

Critics say Trump’s decision helps Putin

Named after late South Carolina Sen. Lindsey Graham, the legislation had sought to clamp down more quickly on the flow of financial resources fueling Russia’s 4 1/2-year-old war against Ukraine. The bill had sought to sanction Russian officials, banks and a shadow fleet of tankers that keeps Russian energy moving.

Trump personally signed the legislation just last month and his move came just two days before a deadline set in the law itself for its implementation.