David Cameron has claimed the "vast majority" of migrants travelling in boats across the Mediterranean are not asylum seekers but people seeking a better life.
The Prime Minister told MPs the migrants have been "tricked and fooled" by criminal gangs, with Britain's role involving action against the gangs and using the aid budget to "mend the countries from which these people are coming".
He faced criticismover the Government's approach to the crisis fromSNP Westminster leader Angus Robertson, who called for refuge and asylum to be offered to those who need it.
Mr Robertson said the UK has an "appalling record" on the resettlement of Syrian refugees and had turned its back on those rescued in the Mediterranean.
The SNP now has two questions during Prime Minister's Questions due to their status as the third largest party.
The session also saw SNP MPs Pete Wishart and Chris Law sit behind the Labour frontbench as the seat row between the two parties appeared to continue.
In his opening question to the PM, Mr Robertson said: "It's a stain on the conscience of Europe that thousands and thousands of refugees have been dying in the Mediterranean when many lives could have been saved.
"Do you agree that the role of the Royal Navy, of the Italian coastguard and of the navies of other European countries are making a profound difference, however, much more needs to be done, including offering refuge and asylum to those who need it?"
Mr Cameron said Mr Robertson was right to praise the Royal Navy's role, noting HMS Bulwark has been playing an "absolutely key role" in saving lives.
He added: "I would part company with you on your next suggestion. What we need to do in order to solve this crisis is two things: one, we need a government in Libya that we can work with so that it's possible to return people to Africa and stop this criminal trade taking place; and second, we need to break the link between getting on a boat and achieving residence in Europe.
"That's what needs to be done. In the meantime, everything Britain can do as a moral and upstanding nation to save lives we will do and we should be proud we are doing."
Mr Robertson said Britain had adopted this approach 80 years ago when it offered refuge and asylum to those people pursued by the Nazis.
But he told the PM: "Now, in contrast, the UK has an appalling record on the resettlement of Syrian refugees and is not prepared to cooperate with other European nations on accepting refugees who have been rescued in the Mediterranean.
"What, do you think it's fair for Sweden and for Germany and for other countries to accept these refugees while the UK turns its back on them?"
Mr Cameron said Britain should be proud of its record on granting asylum, telling Mr Robertson: "When people are fleeing torture and persecution, they can find a home here in Britain.
"But let's be clear: the vast majority of people who are setting off into the Mediterranean are not asylum seekers but are people seeking a better life.
"They've been tricked and fooled by criminal gangs and our role should be going after those criminal gangs, sorting out the situation in Libya, turning back those boats where we can and making sure with our generous aid budget - that this Government achieved 0.7% - that we use that money to mend the countries from which these people are coming.
"That is our moral responsibility and one I'm proud to fulfil."
Earlier, Labour continued to apply pressure on the Government to accept Syrian refugees through a UNHCR scheme adopted by many other European countries.
Currently the Government runs its own scheme that has accepted around 200 of the most vulnerable Syrian refugees, but shadow development minister Gavin Shuker said it should be doing more.
During international development questions, Mr Shuker told the Commons: "We welcome the reintroduction of search-and-rescue in the Mediterranean, it was a shameful decision to withdraw it in the first place and the Prime Minister was right to U-turn.
"But we know the most vulnerable Syrian migrants won't make it to a boat, they won't get here on a plane, they will die in a camp.
"Given that the whole world community has come together to relocate these most vulnerable through the UN - why do you insist on running your own scheme?"
International Development Secretary Justine Greening said Britain was collaborating with the UNHCR on the Government's scheme and stressed that £800 million of aid has gone to help refugees in countries neighbouring Syria.
Ms Greening replied: "We are working with the UNHCR, collaboratively on this. In fact we have had now just over 200 people that we've helped through that scheme.
"But you should also be aware that through the asylum system we have also had 4,000 asylum applications from Syrians.
"But what this also shows critically is that we need to support people where they are - 99% of the refugees in the Syrian crisis are still in those countries that border Syria, that's why the UK has put £800 million into helping them build their lives there, not least including educating their children."
In a statement, Refugee Council chief executive Maurice Wren said Mr Cameron has the chance to lead a "compassionate response" from Europe focused on saving lives and creating alternate routes to safety.
He said: "It's appalling that Europe's collective response to the greatest global refugee crisis in recent memory has been to close off people's escape routes, pull up the drawbridge and leave people seeking safety with no other option than to place their lives in smugglers' hands."