Novak Djokovic says he has no regrets after falling two sets short of becoming the first man in 43 years to hold all four grand slam singles trophies.

The reigning Wimbledon, US Open and Australian Open champion's 6-4 6-3 2-6 7-5 French Open final loss to Rafael Nadal on Monday consigned Djokovic to the very same fate Roger Federer suffered twice at Roland Garros.

The Swiss marvel succumbed to Nadal in back-to-back finals in 2006-07 in his own attempt to join Australian great Rod Laver as the only man in professional tennis to complete a grand slam sweep.

Djokovic, though, offered no excuses for his defeat.

"The better player won today, so congratulations for that," the Serb said.

"He is definitely the best player in history on this surface - and results are showing that he is one of the best players that ever played this game."

Djokovic said while the stop-start match's overnight suspension probably aided Nadal after the Spaniard had lost eight out of the previous nine games immediately before the tournament referee halted play, the first rain delay on Sunday probably helped him.

"Playing conditions were not good. But it's not anybody's fault and it's not the reason why I lost today," he admitted.

"This has been a strange final with delays and conditions and two days' length of match.

"I'm just happy to be in this position, you know, to be playing finals at Roland Garros.

"I could easily have lost the match in fourth round or even more against (Jo-Wilfried) Tsonga, but I managed to come to the finals for the first time in my career.

"I should be happy about that, of course. I will be and I am, but in this moment I am disappointed about this loss because I thought I started to play better in the third set and felt like I could take this match to a fifth set."

The 25-year-old also insisted the pressure to complete a fabled non-calendar-year slam hadn't been a factor in his Roland Garros near-miss.

"I mean, I was excited about this opportunity. Nothing more than that, really."

- AAP