European Union leaders pledged fresh support for Ukraine on Monday amid strained relations with the new US administration of President Donald Trump.

European Council President Antonio Costa, European Commission President Ursula von der Leyen, and other European and Canadian leaders gathered in Kyiv to mark the third anniversary of the Russia-Ukraine conflict.

Costa said EU accession is key to Ukraine's future, calling it the country's most important security guarantee. The remark came after the Trump administration ruled out Ukraine's NATO membership in a potential peace deal with Russia.

Ukraine was given "EU candidate" status in June 2022, four months after the conflict broke out, as a gesture of EU support. However, many expect the path to full membership to be long.

Von der Leyen said Ukraine could join the bloc earlier than 2030 if it maintains its speedy reforms, adding that membership is merit-based.

"If you would just only set a date, then it would also mean the other candidate countries would ask immediately for a date and not a process anymore," she said.

She also unveiled a $3.67 billion EU financial aid package to support Ukraine's strained budget and help purchase military equipment from its domestic industry, among other things.

Separately, EU foreign ministers approved the 16th package of sanctions against Russia in Brussels on Monday, targeting its energy, trade, transport, infrastructure and financial services.

Following the meeting, EU top diplomat Kaja Kallas said she is "optimistic" that leaders will quickly agree on additional funding for short-term military aid to Ukraine, though details will be discussed at the upcoming EU summit on March 6.

Ding Chun, director of the Center for European Studies at Fudan University in Shanghai, described the flurry of EU moves as "a stress response by the European political mainstream to the impact of Trump's U-turn on US policy toward Europe and Ukraine".

"They regard it as both a matter relating to European defense and security and a matter to show EU independence from the US," Ding said, adding it is also an effort to unify member states and strengthen the bloc's cohesion.

The dramatic change of US policy prompted French President Emmanuel Macron to travel to Washington on Monday to meet Trump and mend ties, but their stark differences were in full display in front of the media.

Open disagreement

Macron openly disagreed with Trump on key issues, including whether to label Russia as the "aggressor". Trump also refused to call Russia's president a dictator, after referring to Ukrainian President Volodymyr Zelensky as one.

Trump and Macron did agree on the deployment of European peacekeeping forces once a peace deal is reached.

"They would not be along the front lines," Macron said. "They would not be party of any conflict. They would be there to ensure that the peace is respected."

After the meeting, Trump said Zelensky could travel to Washington this week or next to seal the minerals agreement, which he called "very close", without elaborating.

Macron, in an interview later with Fox News, said he believes a truce in Ukraine is feasible in the next few weeks. A US minerals deal with Kyiv would be one of the best ways to ensure a commitment from Washington, he said.

Agencies contributed to this story.