European Union foreign ministers on Monday agreed to a 2 billion-euro ($2.14 billion) plan to raid their stockpiles and jointly purchase desperately needed artillery shells for Ukraine, diplomats said.

Diplomats said the 27-nation bloc is aiming to supply 1 million rounds to Ukraine over the next 12 months as Kyiv pleads for more firepower to fight off a grinding Russian offensive.

Kyiv has complained that its forces are having to ration firepower as Russia's yearlong invasion has turned into a grinding war of attrition.

Ukraine has told the EU it wants 350,000 shells a month to help its troops hold back Moscow's onslaught and allow them to launch fresh counteroffensives later in the year.

Prior to signing the deal, EU foreign policy chief Josep Borrell said there needed to be a deal, "otherwise, we will be in difficulties in order to continue supplying arms to Ukraine."

"We have to help Ukraine more, quicker and now," said France's Foreign Minister Catherine Colonna.

The first part of the plan involves committing a further 1 billion euros ($1.06 billion) of shared funding to try to get EU states to tap their already stretched stocks for ammunition that can be sent quickly.

The second part would see the bloc use another 1 billion euros to order 155-millimeter shells for Ukraine as part of a massive joint procurement push intended to spur EU defense firms to ramp up production.

Buying weaponry together on this scale is a major new step for the EU, which has seen long-standing efforts to work more in unison on defense propelled forward by Russia's war.

Countries have been wrangling over details, like whether the EU's defense agency or member states would negotiate the orders and if they should buy only from producers in Europe.

Diplomats said the plan on the table targeted sending the first 1 billion euros worth of shells to Ukraine by the end of May and signing the joint contracts by the start of September.

Lithuanian Foreign Minister Gabrielius Landsbergis said the ambition was to supply one million rounds over the next year, but it was not set in stone.

"It is possible that we might not be able to reach it," he said.