The decision left officials on both sides of the Atlantic scrambling to find out how long the pause might last.

Earlier this week, the Trump administration announced it had suspended some weapons deliveries to Ukraine. The Defense Department says the U.S. needs the weapons to be ready for its own contingencies.

Lawmakers, former diplomats and experts questioned the Trump administration’s decision to halt the supply of some air-defense weapons to Ukraine, saying the move risks prolonging the war with Russia and leaving the country more vulnerable to stepped-up missile and drone barrages.