The leaders of many of Europe’s biggest countries on Monday will descend on Paris in an effort to forge a strategy for their own security as President Trump’s envoys prepared for talks with Russia over ending the war in Ukraine without them.

The meeting in Paris was pulled together rapidly, after Vice President JD Vance’s scathing speech in Munich criticizing Europe’s exclusion of far-right groups from power and the fast-emerging American plans to begin peace talks with Russia in Saudi Arabia this week, without the presence of Ukrainian or European leaders.

Expected in Paris are leaders from Germany, Britain, Italy, Poland, Spain, the Netherlands and Denmark, as well as the president of the European Council, the president of the European Commission and the secretary general of NATO.

On their agenda: what Europeans are willing to commit to secure any peace deal over the war in Ukraine in the short term, and in the long term, to secure the continent as it faces an aggressive, expansionist Russia and the predicted withdrawal of the assurance of American support.

The informal meeting was arranged by President Emmanuel Macron of France, who has made calls for increased European sovereignty and capacity for self-defense a hallmark of his presidency. It is expected to be the first of many such meetings between European leaders in the coming weeks, an adviser to Mr. Macron said.

“Europeans must do more, do better and work in a coherent manner towards our collective security,” the adviser, who insisted on anonymity in line with French political practice, said Sunday night.