The UK and France will keep “all options on the table” to stop migrants crossing the English Channel after 27 people drowned on Wednesday.
The UK prime minister and French president said trafficking gangs were risking lives following the worst-recorded migrant tragedy in the Channel.
Four people have been arrested in connection with the fatal crossing.
Five women and a girl were among the dead, France’s interior minister said.
Gerald Darmanin also said two people had been rescued and one was missing.
It was earlier reported 31 people had died, but the total was revised down overnight into Thursday.
Boris Johnson said he was “appalled” by the tragedy, adding the UK would leave “no stone unturned” to stop human trafficking gangs.
The alarm was raised on Wednesday after a fishing boat crew spotted several people at sea off the coast of France.
The International Organization for Migration said it was the biggest single loss of life in the Channel since it began collecting data in 2014.
The prime minister said on Wednesday that while the UK and France had agreed more needed to be done, there had been “difficulties” persuading the French “to do things in a way that we think the situation deserves”.
Speaking after an emergency government Cobra meeting on Wednesday, Mr Johnson said it was clear French attempts to stop the migrant boats leaving “haven’t been enough”.
He said he hoped the French would find a renewed offer of joint patrols along the French Channel coast “acceptable”.
Meanwhile, French officials said Mr Macron had told Mr Johnson “he was expecting the British to cooperate fully, and that they abstain from instrumentalizing a tragic situation for political purposes”.
The UK has pledged to pay France €62.7m (£54m) during 2021-22 to help increase police patrols along its coastline, boost aerial surveillance and increase security infrastructure at ports.
By Nicholas Watt, political editor, BBC Newsnight
Speaking to one senior UK government official, it is clear the Channel crossings have been a huge issue in Downing Street.
They say that, over the last 18 months, they have attended more meetings on this in No 10 than any other issue with the exception of Covid.
I understand that the strong thinking in No 10 is for joint UK and French patrols along the French northern coast.
That would mean British security forces and French security forces – and the reason for that is that it is so very difficult to police the entire coastline.
The reason why that is so significant is that there is a feeling that if you can intercept as many as 75%, or even 90% of the boats crossing, it would have a huge impact.
It could destroy the economic model of the smugglers and then break up their network.
Mr Macron said France would not let the Channel become a “cemetery”. Since the start of 2021, he said, 1,552 smugglers had been arrested in northern France and 44 smuggler networks dismantled.
Despite this, 47,000 attempted Channel crossings to the UK took place this year and 7,800 migrants rescued, Mr Macron added.
French government ministers and officials will meet later on Thursday to discuss their response to the tragedy.
A number of people are believed to have reached the UK in small boats on Wednesday, with people seen being brought ashore in Dover by immigration officials.
It comes amid record numbers of migrants making the crossing from France to the UK.
The Dover Strait is the busiest shipping lane in the world and has claimed many lives of people trying to cross in inflatable dinghies.
It is thought at least 10 other people had died in the past few weeks while attempting to make it.
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