With its strong public support of Ukraine, Europe seeks to give Zelensky some space in the face of U.S. demands while still urging compromises.

The U.S. military said on Thursday a blast on Sunday near a UNESCO world heritage site in Yemen's capital city of Sanaa was caused by a Houthi missile and not an American airstrike.

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.