A new treaty on the handling of migrants at the French port of Calais is set to be signed by Theresa May and Emmanuel Macron, according to reports in the French media.
Press on the other side of the Channel reported a statement from the Elysee Palace which said the treaty would "complete" the Le Touquet agreement, which allows Britain and France to station border officials on each other's soil.
Downing Street declined to comment on the reports, which came ahead of a high-profile UK-France summit at Sandhurst on Thursday.
Mr Macron is understood to be seeking new financial contributions from the UK to bolster security at the port, which has attracted thousands of migrants hoping to sneak on board trains and ships heading for the UK over recent years.
The president vowed during a visit to Calais on Tuesday that he would not allow the recreation of the "Jungle" migrant tent city which was cleared by authorities in 2016.
French media reported the Elysee as saying the new treaty was "still in the process of being finalised", but would focus principally on the handling of unaccompanied minors, asylum requests and family reunions.
It will reportedly include "precise commitments" from the UK to process asylum claims more quickly, accept more young people travelling alone and to deliver "significant" extra sums for frontier protection.
Mr Macron said on Tuesday that the current "Dublin rules", under which refugees are required to seek asylum in the first safe country they reach, were "unsatisfactory" and called for an "integrated" EU system to deal with the problem.
Hundreds of asylum seekers hoping to cross the Channel remain in the area, more than a year after authorities dismantled the sprawling Jungle camp.
Downing Street has so far said only that Thursday's summit will highlight cross-Channel co-operation on issues such as climate change, air pollution, cyber threats and the human genome.
"We have taken a significant number of unaccompanied asylum-seeking children from the area in and around Calais already," Mrs May's spokesman told reporters.