Paris Saint-Germain coach Luis Enrique said he has no idea how long it will take to turn his side back into a European force after a humbling 2-0 Champions League loss at Arsenal on Tuesday.

The French champions, who lost their talisman Kylian Mbappé to Real Madrid in the summer and look like a side in transition, suffered their first defeat of the season.

Goals by Kai Havertz and Bukayo Saka put Arsenal in command before half-time and although PSG hit the woodwork twice they were comfortably contained by the Premier League side.

Luis Enrique, who left out forward Ousmane Dembélé for disciplinary reasons, accepted his share of responsibility for the defeat, but appeared to question his side's fighting spirit.

"Today we were far away from the standards you need in this kind of match. Arsenal were much better in terms of pressure, intensity, they won every duel," Luis Enrique told reporters.

"It's impossible to play for a positive result when you don't win any of your duels on the pitch, their defenders anticipated our attackers and our defenders didn't anticipate their attackers. Arsenal were superior."

The Spaniard led PSG to the semifinals of the Champions League last season as they beat his old club Barcelona in the quarterfinals with Mbappé scoring twice and Dembélé also on target to turn the tie around in the second leg.

They are top of Ligue 1 and beat Girona in their opening Champions League group game, but Luis Enrique said Arsenal were a big step up in quality for his side.

"I can't properly evaluate the level of our team, we will have to wait until the end of the season," he said.

"This was our first big rival at a higher level. We knew from the first minute they would press us high and they did it aggressively and we couldn't cope with that pressure.

"[Arsenal manager] Mikel [Arteta] has been here for five years, I've been at Paris for one year and two months. I don't know where we are. I have a clear idea where I want us to be, but I don't know how much time I will need."