The U.K. agreed in 2022 to pay France some $650 million over three years to help turn back migrants who gather on the French side to cross. Thousands of migrants wait in makeshift camps in and around the port city of Calais in Northern France to attempt the perilous journey.

Beyond the pomp of the French president's first state visit to London since Brexit, all eyes were on the English Channel — and a controversial migration proposal.

Britain will grant asylum to one migrant in France who can prove a family connection to the U.K. in exchange for each arriving migrant taken back by France.