The migrant crisis in the Mediterranean is "reaching to our borders", Theresa May said as she called for European action to tackle the criminals behind the boatloads of people risking the voyage.
The Home Secretary, who was attending talks with European Union counterparts aimed at responding to the emergency, stressed that the UK was playing a role in the search and rescue mission and the effort to target the gangs "making a profit out of human lives".
European home affairs ministers are meeting in Luxembourg to try to hammer out a joint strategy for dealing with the flow of people crossing the Mediterranean.
The European Commission has proposed redistributing around 60,000 Syrian and Eritrean asylum seekers from Italy and Greece to other member states.
But the quota plan is being resisted by a number of countries in the borderless Schengen zone, while Britain has indicated it will use an opt-out to avoid taking part.
Save The Children stepped up the pressure on UK ministers by calling for Britain to agree to take in 1,500 unaccompanied youngsters who had made the crossing to Europe.
Arriving in Luxembourg Mrs May said: "Of course the crisis in terms of migrants who cross the Mediterranean is a problem in two ways. First of all, obviously, lives are being put at risk but secondly, as we see in Calais and elsewhere, it's putting great pressure on European towns and cities which is even reaching to our borders, although we are not part of the borderless Schengen area.
"To deal with this issue in the long term we need to go after the criminal gangs who are plying a terrible, callous trade in human lives.
"We also need to break the link between people getting into the boats and reaching Europe. That means returning people to North Africa or elsewhere, or to their home countries; so that they see that there is no merit in this journey.
"It also means development work in the countries of origin so that we can ensure people no longer have the same incentive to try to get into these boats and risk their lives."
Asked about the British response Mrs May said: "The UK is working with other European countries in a number of ways. We are putting effort into the search and rescue that is taking place - HMS Bulwark but also two Border Force cutters, they are doing that work alongside others.
"But we are also working to deal with these terrible criminal gangs who are making a profit out of human lives and human misery. That is essential work.
"Of course as the UK we also put effort into development aid to help these countries, to stabilise them, to provide the economy that means there is no longer the incentive for the journey."
Italian prime minister Matteo Renzi upped the ante yesterday by suggesting he could begin granting temporary residence permits, which would allow the arrivals free movement into other Schengen states.
In an interview with the Corriere della Sera newspaper, Mr Renzi insisted it was unacceptable that his country was having to bear the brunt of the migration.
“If the European Council chooses solidarity, then good. If it doesn’t we have a Plan B ready but that would be a wound inflicted on Europe,” he said.
Interior minister Angelino Alfano, who was attending the talks with Mrs May, told Sky TG24: “I will say with great clarity: kids, either we do equal distribution of migrants in Europe, or we organise refugee camps in Libya, or we organise a serious policy of repatriation.”
A similar move by Rome in 2011 saw residence permits handed to around 25,000 Tunisian asylum seekers – prompting furious protests from Germany and France.
Prime Minister David Cameron is expected to discuss the issue with Mr Renzi when they meet in Milan tomorrow. No final decisions are likely before the European Council summit later this month.
A Downing Street spokeswoman said: “We do not support relocation. We think our approach should be focused on not creating further pull factors for migrants."
Save The Children urged the Government to take in a "fair share" of youngsters who make the crossing to Europe and increase the number of families fleeing Syria that are offered sanctuary in the UK.
The charity said that more than 5,000 children, many of them travelling without their parents, were among the 54,000 people who have landed in Italy so far this year.
The charity's chief executive Justin Forsyth said: "Britain showed real leadership by deploying HMS Bulwark to help restart rescue operations in the Mediterranean – the Navy is doing incredible work, rescuing nearly 3,000 people in the last weeks alone.
"Without the rescue boats, children would potentially have drowned off the shores of Europe. We ask that people all over Britain join us in saying a heartfelt thank you to the crew of HMS Bulwark for their life-saving work.
"But European leaders must acknowledge the problem doesn't go away when people are brought to shore. For many migrants, including lone children at risk from people traffickers, their ordeal isn't over when they land in Europe. Italy and Greece cannot be expected to bear the brunt of this issue – this is an Europe-wide problem that requires an Europe-wide solution."
"It's up to the Government to decide how they deal with this issue, whether unilaterally or through a joint EU process, but we know that they must act. There are actions that the UK could take now, including committing properly to the existing scheme to resettle the most vulnerable Syrian refugee families and offering sanctuary to a share of the unaccompanied children who have arrived alone on Europe's shores."