Talks between the U.S., Ukraine and European officials to discuss ending Russia's war in Ukraine faltered as Secretary of State Marco Rubio abruptly cancelled his trip to London.

Secretary of State Marco Rubio abruptly pulled out of high-stakes Ukraine peace talks in London—just hours after President Volodymyr Zelensky publicly shot down a major pillar of Donald Trump’s reported ceasefire plan.

The decision by Secretary of State Marco Rubio to pull out of the meeting and an objection by Ukraine’s leader to a key U.S. proposal raised questions about the state of the negotiations.