Britain and France on Friday agreed a new deal to thwart illegal cross-Channel migration after talks between President Emmanuel Macron and Prime Minister Rishi Sunak in Paris towards overcoming post-Brexit tensions.

London will step up funding to France over the next three years to total 541 million euros ($575 million), allowing the deployment of "hundreds" of extra French law enforcement officers along the Channel coast to stop the illegal migration, the British government said in a statement.

Macron said his talks with Sunak marked a "new start" between Paris and London after the tensions caused by Brexit and other bilateral headaches.

"I believe today's meeting does mark a new beginning, an entente renewed," added Sunak.

He acknowledged: "If we're honest, the relationship between our two countries has had its challenges in recent years."

Under the deal, for the first time the UK will help fund a detention centre in France to enhance its ability to cope with the number of people being trafficked across the Channel.

"We don't need to manage this problem, we need to break it," said Sunak.

"And today, we have gone further than ever before to put an end to this disgusting trade in human life."

The new funding from the UK this year is already more than double last year's package worth over 70 million euros that increased the number of French police patrolling Channel shores.

"Over the next three years, the UK's contribution towards this package will be 141 million euros in 2023-24, 191 million in 2024-25 euros and 209 million in 2025-6 euros," the UK government said.