Hollande said France will do whatever possible to see that "the measures that have so badly harmed Cuba's development can finally be lifted" ahead of meetings with Fidel and his younger brother Raul Castro, the duo who have ruled Cuba since its 1959 revolution.
Hollande met first with a smiling Fidel, the iconic 88-year-old father of the revolution, who he said still "had a lot to say". Castro wore a black and white sweat suit over a checked shirt in contrast to the military fatigues that were his trademark before he yielded power to his younger brother in 2006.
Hollande called Fidel a figure of historic stature.
He said his trip came "at a particularly important but also uncertain time," as the United States seeks to restore diplomatic relations with Cuba
after a half-century-long break and European countries scramble to reinforce ties.
Hollande's Cuba trip, the first ever by a French leader, has highlighted the simultaneously cooperative and competitive relationship between the United States and the European Union as both look to increase business with Havana.
Asked if US President Barack Obama would follow suit and make his own visit, White House spokesman Josh Earnest said he "wouldn't rule it out" over the course of the next year.
Since announcing in December that the United States and Cuba would move to renew ties, Obama has used executive authority to relax parts of the embargo, including restrictions on travel and on sending money to the island.
He has urged Congress to lift the full embargo, in place since 1962, but, with both houses controlled by his Republican opponents, he faces an uphill political battle.
Cuba says what it calls "the blockade" has cost it more than $100 billion.
- Call for 'opening' -
Hollande also urged Cuba to open up its economy, saying there was vast interest in doing business with the island.
"Of course, we would like to see your rules relaxed and for our companies to be able to manage their resources more freely," he told a business forum.
"That's not out of self-interest, it's to foster increased investment."
Raul Castro has presided over gradual economic and social reforms since taking over in 2006 from Fidel, who led the revolution that ousted dictator Fulgencio Batista and eventually made Cuba a one-party communist state.
France has joined the Netherlands and Spain in leading an EU push to normalize relations with Cuba, suspended in 2003 over a crackdown on
journalists and activists.
The EU opened talks on restoring ties in April 2014 aiming to persuade Havana to improve its rights record.
The historic US-Cuban thaw has lent new momentum to the process, with Europe keen to position itself politically and economically for when the US embargo is eventually lifted.
Hollande, who is traveling with a delegation of French business leaders, said officials from the two countries would sign a series of agreements
focused on improved access to Latin American markets.
- Human rights rift -
The visit follows a meeting Sunday between Raul Castro and Pope Francis at the Vatican, where the Cuban leader thanked the pontiff for his role in brokering the historic detente between Havana and Washington.
The pope will himself visit Cuba from September 19 to 22, traveling to Havana and the eastern cities of Holguin and Santiago de Cuba.
Hollande, who arrived in Havana late Sunday, said it filled him with "great emotion" to be the first French leader to visit Cuba since it gained
independence in 1898.
He took time out Monday to go for an unscheduled stroll along the Prado, one of the capital's oldest avenues.
The French leader later held a lengthy closed-door meeting with Fidel Castro at the ex-leader's home.
"Before me I had man who made history," Hollande said, adding that Castro "had a lot to say" despite his age and failing health. Castro makes few public appearances.
Hollande later met with President Raul Castro, 83, who has led Cuba since 2006 when Fidel developed health problems and stepped aside.
"They raised the idea of boosting the French-Cuban partnership with respect for the pace and identity of each," an aide to the French president said.
Castro also said France could play a key role in strengthening ties between the EU and Cuba, the aide said.
Hollande earlier had vowed he would "not remain tight-lipped", saying his conversations would not shy away from the issue of human rights, a lingering source of tension in negotiations to restore EU-Cuban ties.