Sir Keir Starmer vowed on Tuesday to build a stronger Anglo-French relationship if he becomes Prime Minister.
He described talks with French president Emmanuel Macron in Paris as "very constructive and positive".
The Labour leader would not be drawn on certain details of the discussion but said he was "very pleased with the outcome".
He said the meeting began with an "exchange of gifts" and covered topics including "the relationship between our two countries" and future "prosperity and security".
Sir Keir said: "We had a very constructive and positive meeting, which as you can imagine covered a wide range of issues.
"It was my first opportunity to say how much I value the relationship between our two countries, particularly when it comes to prosperity and security and how, if we are privileged enough to be elected into power, intend to build on that relationship and make it even stronger than it is today."
Sir Keir added: "We had a very political discussion covering a lot of issues to do with global politics but also it was that opportunity to look at future prosperity, future security, some of the most pressing issues on my mind, on the president's mind."
Relations between France and Britain were fraught under the premierships of Liz Truss and Boris Johnson, largely fuelled by Brexit rows.
Rishi Sunak has already taken steps to rebuild ties with the EU, agreeing the Windsor Framework on Northern Ireland trading arrangements, and with France in particular at an Anglo-French summit in Paris in March.
This followed Ms Truss, as she campaigned to become Prime Minister last year, saying the jury was out on whether Mr Macron was “friend or foe”.
Mr Macron and Sir Keir are believed to have discussed a new security agreement to smash crime gangs behind the “small boats” Channel crisis.
The Labour leader met the French president at the Elysee Palace in an “introductory” meeting, as polls suggest he is heading for No10 next year.
Sir Keir has also said he would seek to renegotiate the Brexit deal struck by Mr Johnson which he has branded “far too thin,” changes which experts are warning may throw up difficult and divisive decisions again.
Ahead of the talks, shadow City minister Tulip Siddiq told Times Radio: “The Government has botched this deal entirely and has ramped up the divisive rhetoric with our closest trading partner.
“Why would they give us a second chance? But I think Keir, and the Labour Party, is trying.
“The main thing he wants to do in Paris is seek a new security agreement with Europe because in Government, if we do win the next election, he wants to talk aut how do we tackle people smuggling, how do we bring gang leaders to justice, it’s something that, we lost in the Brexit deal, that they are trying to negotiate at the moment, the Government is trying to negotiate.
“I’m hoping that Keir’s conversations today in Paris are a bit more optimistic and that if we are in Government, we can do something about the real-time data and intelligence sharing on suspects.”
Sir Keir and Shadow Chancellor Rachel Reeves met business leaders in the French capital before he headed to the Elysee to see the president.
The president and Labour leader did not to make any specific announcements or strike any particular agreement in the talks.
But Health Secretary Steve Barclay slammed Sir Keir’s bid for a new Brexit pact, telling Sky News: “He said he would respect the Brexit deal, now he wants to re-open the Brexit deal.
“The position he is setting out once again is a flip-flop.”
The Macron meeting comes after Sir Keir spent last week meeting fellow centre-left leaders in Montreal, Canada, including the country’s prime minister Justin Trudeau.
That visit followed a trip to The Hague to hold talks with Europol officials on the challenge of tackling people-smuggling gangs profiting from small boat crossings in the Channel.
