A decision by Washington to halt some shipments of critical weapons to Ukraine prompted warnings by Kyiv on Wednesday that the move would weaken its ability to defend against intensifying airstrikes and battlefield advances.

Ukraine said it had called in the acting U.S. envoy to Kyiv to underline the importance of military aid from Washington continuing, and cautioned that any cut-off would embolden Russia in its war in Ukraine.

The Pentagon’s decision – tied to concerns that U.S. military stockpiles are too low – began in recent days and includes 30 Patriot air defence missiles, which Ukraine relies on to destroy fast-moving ballistic missiles, four people familiar with the decision said on Wednesday.

It also includes nearly 8,500 155mm artillery shells, more than 250 precision GMLRS (mobile rocket artillery) missiles and 142 Hellfire air-to-surface missiles, they said.

“The Ukrainian side emphasised that any delay or procrastination in supporting Ukraine’s defence capabilities will only encourage the aggressor to continue the war and terror, rather than seek peace,” Ukraine’s foreign ministry said.

The defence ministry said it had not been officially notified of any halt in U.S. shipments and was seeking clarity from its American counterparts.

A Ukrainian source familiar with the situation said the decision was a “total shock.”

Deputy White House press secretary Anna Kelly said the decision was made “to put America’s interests first” following a Department of Defense review of military support around the world.

“The strength of the United States Armed Forces remains unquestioned — just ask Iran,” she said, referring to U.S. bombing of Iranian nuclear facilities last month.

NATO Secretary-General Mark Rutte said the U.S. needed to take care of its stockpiles but told Fox News that “in the short term, Ukraine cannot do without all the support it can get” when it comes to ammunition and air defence systems.

RUSSIAN AIRSTRIKES

Dozens of people have been killed in recent airstrikes on Ukrainian cities and Russian forces, which control about a fifth of Ukraine, have been making gains in the east.

Senator Jeanne Shaheen, the top Democrat on the U.S. Senate Foreign Relations Committee, said the decision risks Ukrainian lives, undermines Washington’s credibility and will make it harder to end the war.

“This sends a message to not just our allies, like Ukraine and our European allies, but it sends a message to our adversaries, to China, to North Korea, to Russia, that our allies can’t count on the United States,” she told WKBK radio in her home state New Hampshire.

Since U.S. President Donald Trump took office in January, he has softened Washington’s position towards Russia, seeking a diplomatic solution to the war and raising doubts about future U.S. military support for Kyiv.

Trump said last week he was considering selling more Patriot air defence missiles to Ukraine after meeting President Volodymyr Zelenskiy.

Fedir Venislavskyi, a member of the Ukrainian parliament’s national security and defence committee, said the decision to halt shipments was “very unpleasant for us”.

In an email, the Pentagon said it was providing Trump with options to continue military aid to Ukraine in line with the goal of ending the war.

Elbridge Colby, undersecretary of defence for policy, said it was “rigorously examining and adapting its approach…while also preserving U.S. forces’ readiness.”

All weapons aid was briefly stopped in February, with a second, longer halt in March. Washington resumed sending the last of the aid approved under the previous administration, of Democratic President Joe Biden, but no new aid to Ukraine has been announced.

The Kremlin welcomed the news of a halt, saying the conflict would end sooner if fewer arms reached Ukraine.

Kyiv residents expressed alarm at the Pentagon’s decision.

“If we end up in a situation where there’s no air defence left, I will move (out of Kyiv), because my safety is my first concern,” said Oksana Kurochkina, a 35-year-old lawyer.

On the battlefield, a halt in precision munitions would limit the capacity of Ukrainian troops to strike Russian positions farther behind the front line, said Jack Watling, a military analyst at the Royal United Services Institute.

“In short, this decision will cost Ukrainian lives and territory,” he said.