Keir Starmer has hinted ministers are in talks with Iraq, Turkey and Vietnam over deals to stop would-be asylum seekers leaving.
Officials are understood to be hammering out multi-million pound agreements that would see border measures strengthened in each country.
Similar arrangements have previously been reached by the Italian government, but have been heavily criticised by human rights groups.
The Prime Minister told reporters he is "not going to go into the details of any arrangements". But he refused to deny speculation that bespoke agreements are being sought.
Such deals would see the UK pay Turkey, Vietnam and Kurdistan - a semi-autonomous region of Iraq - to stem the flow of migrants leaving.
These nations would be required to strengthen measures on their own borders, and any deal could include a returns agreement. Mr Starmer said: "Anything else we can do to stop people leaving in the first place is the right thing.”
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The Italian government has reached similar agreements with Tunisia and Libya to stop people heading for Europe. But it has led to reports of migrants being forced into Libyan detention camps, where there are allegations of torture.
Mr Starmer has previously praised Italian PM Georgia Meloni's "upstream work". The PM added that his Government has had success with speeding up returns - with around 9,400 failed asylum seekers removed since Labour came to power.
He told reporters on the journey to the G20 summit in Brazil: "We have done a lot of work on returns since we have come into government. We have got I think 9,400 people have been returned.
"We have had the biggest single plane loads of returns going off, I think we have had the three biggest now that have ever gone off, so that is really good on returns.
"Obviously a lot of my time and focus has been taking down the gangs in the first place." He said he'd had discussions with the French, German and Italian governments and had been "pressing hard" on law enforcement.
Referring to the arrest of a suspected small boat engine kingpin following a joint intelligence operation last week, he said: "I was very pleased to see the arrest we saw on Thursday in relation to the Turkish individual.
"That is a very significant arrest in my opinion and I was very pleased that the National Crime Agency (NCA) were playing such a crucial part in that particular operation. So my focus is on stopping the arrivals in the first place which is taking down the gangs. Of course, we have got to get the returns sorted out as well."