A new €5 billion (£4.7 billion) European Union fund will not necessarily guarantee that more weapons will be sent to Ukraine, it has emerged.

Member states agreed that their expected contributions to the Ukraine Assistance Fund, part of the European Peace Facility (EPF), could be partly offset against previous pledges of aid to Kyiv.

The compromise clause, inserted into the deal at the behest of Germany, means the EU’s promise is unlikely to deliver on the headline figure in real terms.

Diplomats told The Telegraph that Berlin, which has promised €7 billion in weapons to Ukraine bilaterally since the start of the war, will not be expected to contribute to the EU’s pot as a result, effectively leaving it short.

The EPF had been considered vital in the effort to replace waning American aid for Ukraine. Kyiv has warned it is losing ground to the Russians while a small group of Republican politicians refuse to back a planned $60 billion aid package from Washington.

As an agreement was reached in Brussels on Wednesday, Josep Borrell, the EU’s top foreign diplomat, said: “We made it. The message is clear – we will support Ukraine with whatever it takes to prevail.”

But it later emerged the €5 billion fund would not contain any new funds from member states to purchase weapons. Instead, European capitals will be able to write off “in-kind contributions” to the EPF against donations already made for Kyiv.

The fund is designed to reimburse EU states back 50 per cent of their donations to Ukraine. Germany has already promised enough bilateral aid to make up for its €1.25 billion contribution to the pot.