A Ukrainian delegation will be in London on Wednesday for ceasefire talks, as European and US officials press for a halt to Russia's war, Ukrainian President Volodymyr Zelensky said.

The talks will be a follow-up to a meeting in Paris last week, in which US Secretary of State Marco Rubio presented Washington's plan for ending the three-year conflict.

US President Donald Trump has been pushing all sides to accept a ceasefire, but has failed to extract any major concessions from the Kremlin despite repeated negotiations and a brief truce announced by Russia's Vladimir Putin over Easter.

"Already this Wednesday, our representatives will be working in London. Ukraine, the United Kingdom, France, and the United States – we are ready to move forward as constructively as possible," Zelensky said on X on Monday.

"An unconditional ceasefire must be the first step toward peace," he added.

Zelensky did not say who else would attend, but Rubio suggested earlier that a US delegation would take part. (AFP)