Home Secretary Theresa May has said practical co-operation and not burden-sharing is the way to stop tens of thousands of migrants fleeing the turmoil in north Africa from flooding Britain.
Joint operations between UK and French officials have already helped cut the number of people trying to get to Britain from the Port of Calais by 70%, she said.
Amid concerns that tens of thousands of migrants from north Africa may head to Calais to try to make their way to Britain, Mrs May said "strong practical action was needed".
"We need lasting practical co-operation and not burden-sharing," she said.
Under the Schengen Agreement, citizens in 25 mainland European Union (EU) nations are allowed to travel across borders without having their passports checked.
But the deal is under threat as tensions have risen over the fleeing migrants after Italy handed more than 25,000 Tunisians temporary permits to travel, effectively giving them unobstructed travel around the 25 EU nations. The UK and Ireland are not part of the agreement.
Speaking at Calais town hall after inspecting the cross-border security operations at the ports, Mrs May said: "Continued pressure from illegal immigrants in France is a joint problem for both the UK and France and as such requires a joint solution. We are committed to continuing to ensure the border is impenetrable."
She added: "We need strong practical action to support countries in the region in their humanitarian and migration control efforts, and I'm committed to working with the minister to ensure the international response is swift, practical, effective and makes a real difference. We need lasting practical co-operation and not burden-sharing."
Mrs May said the partnership "in the face of immigration, terrorist and organised crime threats" has "helped create one of the strongest borders in the world".
Such efforts had "contributed to a 70% decrease in the number of people attempting to cross our border illegally", she said.
