President Donald Trump rocked Kyiv and its European backers by briefly suspending Washington's military aid for Ukraine after a bust-up with his counterpart Volodymyr Zelensky.

The proposal from EU foreign affairs chief Kaja Kallas seeks to get countries in the bloc to "accelerate and focus" on meeting Kyiv's most pressing needs as its forces struggle against Russia.

"Participating states are encouraged to deliver military support to Ukraine in 2025 with a provisional value of at least EUR 20 billion, and potentially reaching EUR 40 billion pending Ukrainian needs," the document seen by AFP said.

The proposal says that countries should contribute according to their "economic weight" and part of the plan would involve giving Ukraine two million artillery shells in 2025, worth five billion euros.

Just under two billion euros of the total would also come from EU funds tapping profits from Russian frozen assets and previously pledged to Ukraine, the document said.

Diplomats said that the plan faces opposition from large economies such as France, Italy and Spain, which have been accused of pushing below their weight on aid for Ukraine.

They said the plan could get round a blockage by Hungary -- Russia's closest friend in the EU -- by opening the plan to only countries willing to join, but discussions were ongoing.

Officials said the plan could be opened to countries outside the bloc such as Britain and Norway.

EU foreign ministers meeting in Brussels on Monday are expected to discuss the proposal ahead of a summit by leaders later in the week.

EU leaders gave their initial green light for further work on the plan at a meeting earlier this month.

Europe is looking to ramp up its support for Ukraine, with fears that Trump could force Kyiv to accept an unfavourable peace deal to end Russia's invasion.

Washington resumed its aid to Ukraine this week after Kyiv agreed to a US proposal for a 30-day ceasefire, but Moscow has refused to sign up for the initiative so far.

Fatigued Ukrainian forces are currently being pushed back along the front line, with Russia close to retaking the Kursk region that Kyiv captured last year.