PARIS (AP) — France and Britain signed an agreement Sunday to share intelligence in their joint fight against the human traffickers who are illegally smuggling migrants across the English Channel.

French Interior Minister Gerald Darmanin said the deal to set up a French-British intelligence unit would allow for better exchanges of information about smuggling networks.

British Home Secretary Priti Patel said the new unit “will crack down on gangs behind vile people smuggling.” Patel crossed the Channel to visit the northern French city of Calais to sign the deal with Darmanin. She described levels of illegal migration across the waterway as “unsustainable."

People smuggling across the Channel and migrant camps that regularly spring up along France's northern coast have proven to be an intractable problem for both governments. Britain's previously strong economy and need for farm and restaurant labor drew migrants from around the world who could speak some English. Calais over the years has unwillingly hosted rudimentary, overcrowded migrant camps that sprung up, slums so poor and violent that one was dubbed “the Jungle.”

Darmanin said he pressed Patel for additional British help, including officers and equipment, to root out smugglers “who profit from the human misery of the people who want to cross the Channel and who are not punished enough.”

“It’s very important that our British friends realize that if the migrants come here in Calais, it’s not for the beauty of the city but it’s to cross the Channel,” he said. “The British government did a lot to protect the French coast, but we need more means.”