The United Kingdom and France have agreed on a new three-year deal to curb undocumented migrant crossings in the English Channel. Under the agreement, France will step up patrols along its coast, increasing the number of officers by more than 50% to 1,400 by 2029, while the UK will provide up to €766 million ($897 million) in funding. Almost a quarter of the money will be paid only if the measures prove effective. The UK Home Secretary Shabana Mahmood and French Interior Minister Laurent Nunez were expected to sign the three-year agreement in France on Thursday. What will the UK-France new border security deal cover?…