Increased patrols and technology will be deployed along France's beaches under a new agreement between Paris and London aimed at stopping illegal migration across the Channel.

A growing number of migrants have tried to reach Britain across the perilous and busy shipping lane in recent months, with four deaths recorded in 2019 and seven so far this year.

The deal will see French patrols doubled from December 1, with drones and radar used to detect those attempting to cross, Britain's Home Secretary Priti Patel said Saturday.

Welcoming the deal, Patel said it would help the two countries with their "shared mission to make channel crossings completely unviable".

The issue has been a source of tension, with Britain accusing France of not doing enough to stop the crossings.

In September, French authorities said they had intercepted more than 1,300 people trying to reach Britain, including a handful who had attempted to swim the 30-odd kilometres (18 miles) across the Channel.

Around 6,200 attempted the crossing between January 1 and the end of August, with inflatable boats, paddleboards, kayaks or even lifejackets to keep them afloat.

Northern France has long been a magnet for people seeking to smuggle themselves to Britain in small boats or in one of the thousands of trucks and cars that cross over daily on ferries and trains.