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The White House has abruptly halted shipments of several high-value weapons to Ukraine, raising concerns about Kyiv’s defensive posture as Moscow’s summer offensive gains ground.

Among the weapons are interceptors for Patriot air defence systems, precision-guided artillery shells and missiles launched by Ukraine’s F-16 fighter jets, according to senior US officials. The move was driven by concerns over Washington’s own military readiness with stockpiles running too low, they said.

Washington’s decision will send a chill across Ukraine at a precarious time for Kyiv, as it relies on these for air defence and frontline support. It comes three days after Russia’s largest combined missile and drone bombardment on Ukraine since the start of its full-scale invasion, a sharp escalation that has further dimmed already faint hopes of a negotiated end to the war.

‘‘We counted on many of those systems as they were promised,” said a Ukrainian official involved with their country’s military strategy, adding that it would expose civilian infrastructure to attack. “That significantly affects our planning.”

The weapons affected include dozens of PAC-3 interceptors for Patriot air defence systems, dozens of Stinger man-portable air defence systems, precision-guided artillery shells, more than 100 Hellfire missiles, and AIM missiles launched by Ukraine’s NASAMS and F-16 fighter jets, according to the officials.

Anti-tank systems such as the AT4 grenade launcher have also been affected, while some 250 Guided Multiple Launch Rocket System (GMLRS) rounds used to strike ground targets accurately at long distances have been held up.

The White House declined to confirm the specific weapons systems that were stopped. The Pentagon is still offering options for aiding Ukraine militarily, but is “examining and adapting its approach”, said Elbridge Colby, Pentagon under-secretary of defence for policy. Colby dismissed criticism of the move as an attempt to “portray division [within the Pentagon] that does not exist”.

Ukraine’s presidential administration and defence and foreign ministries did not respond to requests for comment. Politico earlier reported the halt of some weapons to Ukraine.

The decision to withhold the weapons came in early June but is just now coming into force, a person familiar with the matter said. Some weapons were already en route to Ukraine when they were halted, according to that person.

Russia has enhanced its Iranian-style attack drones in recent months, enabling them to strike with greater speed and lethality deep into Ukrainian territory. Moscow has expanded production of the drones, saturating Ukrainian defences and forcing Kyiv to use increasingly scarce interceptors. 

Russia has also increased the frequency and size of its air attacks significantly, launching a record 5,438 drones against Ukraine in June, according to data from the Ukrainian Air Force, or nearly a 30 per cent increase from the 4,198 drones launched in March. Russia can now attack Ukraine in a day with as many drones as it did in a month compared with a year ago, Kyiv’s air force data shows.

Ukraine has experienced just two days without Russian drone and missile attacks over the past year and a half, said foreign minister Andriy Sybiha on Monday.

Alongside its attack drones, Russia often launches a menacing mix of cruise and ballistic missiles. This adds to the difficulty facing Ukraine’s air defence units as they try to intercept them.

“The absence of Patriot anti-aircraft missiles will lead to an increase in successful Russian missile strikes on Ukrainian cities, which will lead to an increase in civilian casualties,’’ said Viktor Kevlyuk, a military expert at the Kyiv-based Centre for Defence Strategies. ‘‘The absence of GMLRS missiles will limit the ability to deliver missile strikes on targets in the operational depth.”

European and Asian sources could compensate for some of the reductions, but it would be harder for Ukraine’s army in the meantime, he said.

US President Donald Trump has long urged Russia and Ukraine to negotiate a ceasefire and end a war that began with Moscow’s annexation of Crimea in 2014 before the Kremlin’s full-scale invasion in 2022 brought about the bloodiest war on European soil in generations.

Russian President Vladimir Putin appears confident that his army can continue pounding Ukraine from the air and advancing on the battlefield at its fastest pace since November.

‘‘Decisions to withhold critical aid from Ukraine are not likely to bring about President Trump’s desired ceasefire,” said George Barros, an analyst focused on the conflict for the Institute for the Study of War, a Washington-based think-tank.