"These discussions are not easy, not least in the wake of this horrific violence. But we all support President Trump's push for peace," Rutte said of US-led talks during a surprise visit to the port city of Odesa, where he met with Ukrainian leader Volodymyr Zelensky.

Zelensky meanwhile called for effective preparation of a foreign troop contingent to deter Russia from attacking Ukraine again should a peace deal be secured.

"Britain, France and other NATO countries are already actively preparing the ground for a security contingent in Ukraine. It is important that we all be fast enough and efficient in this process," he said.

Zelensky also told Rutte that Ukraine urgently needed air defence systems after recent Russian missile strikes killed dozens of civilians.

"Absolutely everyone sees how acute Ukraine's need for air defence systems and missiles is. We talked about this a lot today," the Ukrainian leader said.