The French president and the PM are co-hosting the Franco-British Summit on the final day of Macron's state visit to the UK.

U.K. Prime Minister Keir Starmer and French President Emmanuel Macron plan to sign declarations aimed at strengthening coordination between British and French nuclear deterrence forces and advancing joint weapons development,

Britain and France will join together to use nuclear weapons against any “extreme threats” towards Europe, Sir Keir Starmer and Emmanuel Macron have declared. A newly-signed declaration by the leaders will state that the two countries’ nuclear deterrents are independent but can be co-ordinated in a joint attack on Europe’s enemies.