05:24 BST
Damian Grammaticas
Political correspondent
At this summit, the UK and France are promising that they will make progress on “new and innovative solutions, including a new deterrent” to “break the business model” of the gangs smuggling people across the Channel.
The deal that’s been under discussion envisages the UK returning migrants to France. For each individual taken back, France would transfer one asylum seeker to the UK, probably someone with a family connection or genuine reason to seek sanctuary here.
What’s not known are the potential numbers involved and whether final details could be agreed this week.
When it comes to defence, the UK and France will sign a declaration saying that their independent nuclear deterrents could, in future, be co-ordinated, if an adversary was threatening either country, and there were no extreme threats they would not confront together.
There will also be joint development of new missiles and air defences, and support for Ukraine.