Leaders gather at Versailles after atrocity in Ukraine

And arriving at Versailles, she sought to make the response to conflict part of European collective responsibility, suggesting that the EU's future and its citizens' freedoms are at stake too.

"It is a moment where we see Putin's war is also a question of the resilience of democracies," said von der Leyen who, like dozens of other dignitaries, arrived at the palace to be welcomed by French president Emmanuel Macron and the sound of a French military band.

Yet, despite the pomp, and the grandness of the setting, no major breakthroughs were foreseen.

EU leaders were expected to agree to increase military spending and cooperation, and to agree to phase out dependence on Russian fossil resources, as they've been discussing for days.

They also were scheduled to discuss possible new bond issuance to finance energy and defence spending — but without taking a final decision.

Nor was any decision expected on cutting imports of Russian fossil resources, or on speeding up Ukraine's accession to the European Union because of the depth of division among member states.

On Ukraine's dramatic appeal for a form of fast-tracked membership last week, EU leaders were instead expected to state in a final declaration that, "Ukraine belongs to our European family."

The summit in the French royal palace had been planned before Russia launched its invasion of Ukraine on 24 February.

Even so, the location has stirred some discomfort among observers who recall how it was the setting for the peace treaties signed in 1918 that laid the groundwork for the second world war, which followed two decades later.

The meeting at Versailles comes against the background of the Russian invasion of Ukraine that has threatened to unravel the post-war security order for the European continent.

These days, the positions of EU member states suggest there may be no quick and simple way the Russian challenge.

Most eastern and central European leaders, who have been warning about the Russian threat for years, back harder sanctions and cutting Russian gas and oil imports.

Germany, however, along with Italy, Hungary, Austria, which are among those most exposed to Russian energy imports, are not keen on a quick phase out Russian energy despite the dependencies they create and the large sums of money that flow to the Kremlin as a result.

"We should not only isolate but cripple Putin's economy, we have to make sanctions much harder, much faster," said Latvian prime minister Krišjānis Kariņš, who called for a full stop to EU energy imports from Russia.

"What do we have to lose?" Kariņš asked. "We have to defend democracy, and stop Russian neo-imperialism," he said, explaining that Europe was relying on Ukraine to fight on its behalf to safeguard democracy.

No fast-track

States like Latvia also back Ukraine's swift EU membership, but there is no immediately clear path forward there, either.

Dutch prime minister Mark Rutte, was among those on Thursday to tamp down expectations that Ukraine would be an EU member state any time soon.

"The Netherlands stands shoulder to shoulder with Ukraine, but there is no such thing as fast-tracking accession," said Rutte. "I want to focus on what we can do for Ukraine tonight," he said, but "accession is for the long-term."

EU leaders were expected to say in their final declaration that Russia had "grossly" violated international law and to call for the country to "be held to account for" a "war of aggression."

Moscow should cease its military action and withdraw from "the entire territory of Ukraine immediately and unconditionally," they were expected to say.

EU leaders were also expected to refer to a part of the EU treaty, which says that if "a member state is the victim of armed aggression on its territory, the other member states shall have towards it an obligation of aid and assistance by all the means in their power."

That is far from a military assistance of the kind shared among Nato members, where all come to the defence of any member subjected to an attack.

Even so it was a nod to the concerns of Finland and Sweden, which are outside the military alliance, but have been seeking greater reassurance of European support in the event of a spillover of the Ukrainian war.

EU leaders also pledged to increase defence expenditures — but they will not give a specific amount during the summit, or make an overall pledge to reach the level of 2 percent of GDP long sought by the United States and Nato.

The EU would "take more responsibility" for Europe's security and "contribute positively to global and transatlantic security and is complementary to NATO," the leaders were expected to say.

As for joint projects involving preparations for hybrid warfare, strengthening cyber-resilience, and enhancing military mobility and space projects, leaders were expected to task the commission with identifying investment gaps — by mid-May.