President Emmanuel Macron is visiting the port city of Calais, where hundreds of migrants hide out while trying to make an end run to Britain.
The northern city, laced with high fences and a wall, is the closest point between France and Britain, with two cross-Channel transport systems, the Eurotunnel and ferries that are a magnet for migrants.
Macron is visiting a migrant center before meeting security forces in Calais on Tuesday.
Macron wants changes to the 2003 Touquet Accords that effectively moved the British border to Calais and have left France with the problem of dealing with migrants refused entry into Britain. He is meeting with British Prime Minister Theresa May in London on Thursday.