Generals from 27 countries will gather in London this week to start wargaming the potential deployment of troops, ships and planes to Ukraine.

Sir Keir Starmer announced on Saturday that planning for a peacekeeping force in the event of a ceasefire was now entering an “operational phase”.

The Prime Minister was speaking after chairing a video call of world leaders who have joined a “coalition of the willing” to enforce any peace deal.

He said they had agreed to send generals to a meeting on Thursday to discuss which military capabilities each member could provide.

The Telegraph has been told that the group of allies has still not reached a concrete agreement to deploy any forces to Ukraine.

A European military leader said more discussions were needed over whether the coalition of the willing is even able to put boots on the ground.

Sir Keir said Britain was ready to play a “leading role” and put “troops on the ground and planes in the sky”.

It is understood that the Royal Navy would also be likely to deploy ships to the Black Sea in the event that Russia agrees to a peace deal.