The European Union on Monday agreed to add two billion euros ($2.1 billion) to a fund used to help arm Ukraine, as it seeks to ensure it can keep delivering weapons to Kyiv.

The 27-nation bloc has drained a "peace facility" budget originally meant to last to 2027 in just 10 months of war as it has covered the cost of some arms being sent to battle back Russia's invasion.

"The EU remains committed to provide military support to Ukraine and other partners alike," EU foreign policy chief Josep Borrell wrote in a social media post.

The European Peace Facility was set up last year to help the European Union fund military assistance to its international partners as the bloc looks to increase its global clout.

Russia's invasion of Ukraine in February saw the vast bulk of the fund diverted to help arm Kyiv, as Brussels broke a long-standing taboo on not paying for arms deliveries.

Only around 800 million of the facility's original budget of 5.7 billion euros to 2027 was left in the kitty.

EU foreign ministers meeting in Brussels on Monday reached a "political agreement" to add an extra two billion euros to the fund next year, a statement said.

That amount could rise to 5.5 billion euros by 2027 if member states agree later there is a need, it said.

The fund has been used to reimburse arms supplies by individual EU countries to Kyiv.

So far, together with its member states, the European Union has committed about eight billion euros of military support to Ukraine, which is about 45 percent of the amount the United States has given.