Kyiv is working with allies on security guarantees akin to NATO's mutual protection pledge, Ukraine's president Volodymr Zelensky has said. Officials from Ukraine and allies the U.S., the U.K., France and Germany met in London on Thursday in a week when a peace proposal was produced which outlined an Article 5-like agreement which would be backed by Washington.

The president said he has a "deadline" in mind for talks to make progress, though he did not say what it was. Trump administration officials say they had initially hoped to have secured a negotiated settlement before the 100th day of the president's second term next Tuesday, but that that goal now seems like a pipedream.

After the Ukrainian leader criticized President Trump’s proposed peace plan, U.S. officials again threatened to walk away from negotiations.