It is "a turning point on the history of European integration," EU foreign policy chief Josep Borrell told a media conference on Monday.

European Council President Charles Michel said it took just "a few hours" on Saturday for EU governments to "synchronise" their support for Ukraine, agreeing to activate a European Peace Facility (EPF) to pay for arms procurement and delivery.

"It was a defining moment for European defence," he said.

Analysts concurred.

"The decision to supply arms to Ukraine by using the European Peace Facility constitutes a pivotal moment for European defence, given its scale, its nature and its speed," Pierre Morcos, a visiting fellow at the Washington-based Centre for Strategic and International Studies (CSIS), told AFP.

The EPF, a fund separate from the EU's budget and the bloc's usual procedures over allocating money, holds five billion euros ($5.6 billion) that only EU member states can disburse.

The EPF decision-making process allows "constructive abstention" by an EU country, and Michel's job was to persuade reluctant member states to not vote against opening up the fund for Ukraine, which would have scuppered the measure, EU officials told AFP.

Three countries ended up abstaining, Borrell said.

That allowed Europe to respond to a plea from Ukrainian President Volodymyr Zelensky for weapons and ammunition so his forces can defend their country against the Russian invaders, and it was "another taboo that falls," Borrell said.

Zelensky had sent Michel an extensive wish-list or armaments, seen by AFP. It included anti-tank and Stinger anti-aircraft missiles that Ukrainian soldiers have been trained to use.

Several EU countries possess those type or weapons in their arsenals and were in a position to quickly supply them to Ukraine.

- 'A milestone' -

Poland, which borders Ukraine, offered to be the hub for the arms deliveries. They started to be transported into Ukraine from Saturday and were said to be "significant".

The United States also stepped up by offering transport aircraft for the shipments to Poland.

The EPF funds allow the EU to reimburse the countries donating the lethal aid to the tune of 450 million euros. Another 50 million euros from the EPF is going to pay for equipment and fuel.

"It's really rather remarkable," said Arnaud Danjean, a conservative MEP and military veteran specialised on defence matters.

"A milestone has been achieved, but you need to also bear in mind that many announcements have been made, some of them neither wise nor feasible, such as sending fighter jets," he said, referring in the latter case to words uttered by Borrell that were later watered down.

"The weapons now need to be handed over, and everything depends on what the situation on the ground is," Danjean said.

Ultimately, though, he said the bold political moves seen by the EU in the past couple of days "show a new mindset in Europe and that will accelerate thinking on European defence".

Morcos of the CSIS noted that, in the past, the EU had the tools to act but was hobbled by "taboos and a lack of strategic culture".

Now, "the war in Ukraine seems to have acted as a catalyst".

The decision by Germany to U-turn on its long-held refusal to export arms by pledging to deliver to Ukraine 1,400 anti-tank rocket launchers and 500 Stinger missiles was among the most eye-opening developments.

Just as surprising was Sweden's commitment to supply 5,000 rocket launchers and Finland's announcement Monday to provide 1,500 rocket-launchers and 2,500 assault rifles.

An EU official said that several non-EU countries have contacted Michel to contribute financially to the weapons-supply effort.

"We have moved further this weekend than we have in the past 20 years," Danjean said.

"Europe had the instruments, the means, the capacity, but it always lacked political will. Vladimir Putin has managed to line up the European planets," he said.