Britain and France will spend £1.5bn developing the next generation of drones, in a sign of closer co-operation over security and defence, reports Sky News.
The prime minister and the French president are to discuss how they can work together to fight terrorism at a summit in Amiens, France.
David Cameron will claim the UK is safer as part of the European Union and membership "gives greater security and greater capacity to project power".
He is due to say: "The UK and France are proud allies.
"Our meeting here in Amiens is an opportunity to discuss how we can work even more closely together to keep our people safe.
"I am convinced that the UK's membership of the EU gives us greater security and greater capacity to project power globally.
"In an ever-more uncertain world, we gain from our membership of these international organisations."
Counter-terrorism, the migration crisis, Syria and Libya will be discussed at the Amiens summit, the first since the Paris terror attacks.
It will also be attended by home secretary Theresa May, foreign secretary Philip Hammond and defence secretary Michael Fallon.
The PM is expected to announce more information sharing and greater co-operation between British and French security and police forces.