It was unclear where they were being sent from, but three Nato nations have them – Slovakia, Bulgaria and Greece. 

Mr Zelensky appeared to concede Ukraine’s ambition to join Nato would not be realised, choosing not to mention the transatlantic alliance but instead proposing the creation of a new association to respond to global conflicts.

“We propose to create an association: U-24. United for Peace. A union of responsible states with the strength and conscience to stop conflicts. Immediately,” he said. 

“Provide all necessary assistance within 24 hours. If necessary, with weapons. If necessary, with sanctions, humanitarian support, political support, money. Everything we need to keep the peace.” 

During his address, a privilege rarely afforded to foreign leaders, Mr Zelensky told Congress: “Ukraine is grateful to the United States for its overwhelming support.” But he added: “I call on you to do more.” 

Mr Zelensky demanded the US impose more financial sanctions on Russia, saying: “All American companies must leave the Russia market immediately… All American ports should be closed to Russian goods.”