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 defense missiles, which Ukraine relies on to destroy fast-moving ballistic missiles, four people familiar with the decision said on Wednesday.