Under pressure over the record number of migrants crossing to the United Kingdom in small boats, Sunak met Macron at the COP27 climate summit - their first in-person meeting since Sunak became prime minister on October 25.
Relations between the UK and France had soured, first under Boris Johnson, and then only to worsen when Sunak's immediate predecessor, Liz Truss, questioned whether Macron was a friend or foe during her campaign to become prime minister.
Sunak, who hopes to reset ties, said the meeting with Macron was great, offering an opportunity to work closely with France and other countries to tackle illegal migration, which has resulted in large numbers of migrants arriving in southern England.
"You will hear more details about that in the coming weeks, as those conversations happen amongst all our teams," he told reporters in Egypt.
"I'm actually leaving this with renewed confidence and optimism that working together with our European partners, we can make a difference, grip this challenge of illegal migration and stop people coming illegally."
Shortly afterwards, Sunak's spokesman said the two countries were in the final stages of agreeing a new deal to curb the surge in migrants making their way to England in the boats.
"A deal is being discussed and I think is in its final stages," the spokesman said.
UK officials have previously said they would like to have their own immigration officers on the ground in France, working alongside French policemen to prevent more boats from leaving French beaches.
France has resisted such calls over concerns the move would threaten its sovereignty, UK officials have said.
So far this year, almost 40,000 people have crossed the Channel in small boats, up from 28,526 last year.
