Macron has threatened to overhaul the agreement with demands that may include more British funding as well as requests to take in more refugees and unaccompanied minors as part of a larger effort to prevent migrant camps from mushrooming in Calais.
In last year's presidential election, Macron suggested he may tear up the 2003 Le Touquet agreement, which established French border controls at UK Channel ports and British border controls in Calais.
While the previous government bulldozed a vast tented camp, dubbed the "jungle" and once home to around 8000 people on the outskirts of the town in late 2016, several hundred asylum seekers, refugees and economic migrants remain in Calais and others continue to come, usually seeking to make it to Britain.
Britain will pay tens of millions of pounds (dollars) toward border security in France and support French military missions as part of moves to bind the countries closer together after Brexit.
"Eighty percent of those fit, young men that have been camping over the Calais jungle have traipsed through the Schengen area, the open border system and they have marched through to Calais, and they have not been stopped by successive governments in France, including Mr. Macron".
But now three CH-47 Chinooks will "provide a niche capability providing logistical support but also saving lives by avoiding the need to move troops by ground where they are more vulnerable to attack".
Italy's focus is on Niger, a key transit country for tens of thousands of people arriving in Libya which is itself the launchpad for many Europe-bound African migrants, from where they attempt risky sea crossings to Europe. To help shoulder the financial burden, Macron is now insisting the United Kingdom provide further resources. The Home Office will also help key partners in Africa to tackle immigration crime.
In exchange, France will agree to commit troops to the UK-led North Atlantic Treaty Organisation deployment in Estonia next year, aimed at providing a deterrence in the face of an increasing threat from Russian Federation.
The PM said: 'Today's summit will underline that we remain committed to defending our people and upholding our values as liberal democracies in the face of any threat, whether at home or overseas.
"Our friendship has always gone far beyond defence and security and the scope of today's discussions represents its broad and unique nature", she added.
'What is clear from the discussions we will have today is that a strong relationship between our two countries is in the UK, France and Europe's interests, both now and into the future'.
Only 6% believe leaving the European Union has improved the UK-France relationship, while 28% said it would make no difference. Data are weighted to the profile of the population.