The Netherlands captain joined PSG this week as a free agent despite being heavily linked with Barca for the past year. "What I can say is that I made a different choice," Wijnaldum said in Saturday's press conference.
"It was a difficult choice. We negotiated with Barcelona for four weeks, but we have not come to an agreement. PSG was more decisive and faster. The project also really appealed to me. But it was difficult. I have to say that I also thought I would go to Barcelona. That was the only club that was really interested in me for a long time."
Barca coach Ronald Koeman had monitored Wijnaldum since being appointed as the club's coach last summer in August. Wijnaldum, who spent five seasons at Anfield, was keen for his future to be sorted before the start of Euro 2020. Netherlands take on Ukraine in their Group C opener on Sunday.
"During the European Championship you want to be one hundred percent focused on the tournament," he said. "It was a hectic week in which I had to make choices. They are two big clubs that I would like to play for. It's a relief that I've made the choice before the European Championship, because it's going to play in your head anyway."
Wijnaldum, meanwhile, said he and his teammates were surprised to see a small plane fly over the Netherlands' European Championship training ground in the town of Zeist on Saturday pulling a banner that read in Dutch: "Frank. Just 4-3-3!"
The message in the banner was directed at Netherlands coach Frank de Boer, who has been criticised for not using a more attacking formation (4-3-3). De Boer said he will start Sunday's match at the Johan Cruyff Arena with his regular 3-5-2 setup. "Thanks for the tip, but it's still 3-5-2," De Boer said about the banner.