Kamara is out of contract at the end of the season and has been heavily linked with a move away from Marseille on a free transfer.
Newcastle are amongst the clubs who are interested in snapping him up next summer for no transfer fee, along with Bayern Munich and Barcelona.
Marseille have been in talks over a new deal with the player’s agents and Longoria confirmed that the negotiations have picked up pace between the club and Kamara’s representatives.
The Marseille president stressed that there needs to be will on both sides if the talks are to be successful.
He claimed that the club have been trying out different formulas with the player’s representatives to reach an agreement but stressed that both sides need to do their bit to work out a deal.
Longoria told French sports daily L’Equipe: “The talks have been open for a long time, they have intensified lately.
“He is an important asset for the club and I hope he will stay. But we are not the only party in the negotiations, there needs to be a general will.
“Football is changing. 20 years ago, clubs had extraordinary power over players, too much.
“In recent years, we have shifted into a game where the players have taken a lot of the power.
“We came up with different formulas to find a pattern where everyone would thrive and feel ready to continue.
“Saying that you have offered the maximum during negotiations is not being respectful towards the other party.
“It is a game, the ball is in the middle and everyone must play a part.”
Kamara recently claimed that he has left his agent to negotiate the new contract and listen to offers from other clubs.
