By Idrees Ali and Sabine Siebold (Reuters) -NATO military leaders are expected to meet on Wednesday to discuss Ukraine and the way forward, U.S. and NATO officials said on Tuesday, as Washington and European capitals work out details of what security guarantees might look like for Kyiv.

Special U.S. envoy Steve Witkoff says Russian leader Vladimir Putin agreed to allow the U.S. and Europe to offer Ukraine a security guarantee resembling NATO's collective defense mandate.