Ties between the two firms have been strained since Japanese authorities arrested former Nissan chair Carlos Ghosn in 2018 on charges related to misuse of company funds and underreporting of his personal salary.
In late October, Renault's Thierry Bollore was dismissed from his chief executive role in an attempt to save relations with Nissan's top bosses. A replacement is expected to be announced in the coming days.
Media reports have suggested that Nissan's board is figuring out how a split from its alliance with Renault could work and what other firms it could look to work with.
Speaking at the World Economic Forum in Davos, Switzerland on Wednesday, chairman of Renault, Jean-Dominique Senard, dismissed the claim, saying the spirit between the two firms was already "totally changed" from a few months ago.
"Questions about the alliance; 'What are the new challenges? How we can get out of the situation?' were in every mind, so I can understand that," said Senard, before claiming that the relationship was back to being as healthy as it was 20 years ago.
Bullishly describing the relationship as "extraordinarily positive," Senard added that the two management teams were talking every day and there was the kind of relationship not enjoyed for at least a year.
"We are now shaping up the whole thing in a way that we can only have positive news in the near future," he added.
The Renault-Nissan partnership has the French firm as the dominant player as it holds a much greater stake in Nissan than the other way around. Voting rights in the boardroom therefore favor the French firm, to the annoyance of some Japanese executives.
Renault shares have dipped more that 30% over the past 12 months and the firm's debt ratio currently stands at 1.01 – meaning the firm's total enterprise value only just eclipses what it owes.
When asked if Renault could improve relations with Nissan and lower debt in one stroke by selling down its stake, Senard claimed that was not a topic for immediate discussion.
"Nothing is fixed for eternity, but the priority today is to make sure that things are working well on the industrial part, that's the key," Senard said.