Prime Minister Sir Keir Starmer has said military planning to protect a potential Ukraine ceasefire is moving to an "operational phase" after a virtual meeting with 29 other world leaders.

Military leaders will meet in London on Thursday "to put strong and robust plans in place to swing in behind a peace deal and guarantee Ukraine's future security", Sir Keir said.

The meeting follows Ukraine agreeing to a 30-day ceasefire after talks with the US. Russian President Vladimir Putin said he agrees with the idea, but set a number of pre-conditions for peace.