(CNN) Neymar says the decision to leave Barcelona was "one of the toughest" of his life after completing a world-record move to Paris Saint-Germain and has insisted his move was not motivated by money.

The forward completed his $263 million transfer to the French capital Thursday, just a week after Barcelona officials had said he was "200%" staying with the Catalan club.

Unveiled to the media Friday, the Brazilian said the decision to join the French club came from his desire for a bigger challenge.

Neymar told CNN Sport: "They're one of the biggest clubs in the world, I want to be part of the history. I came here to make history and win unprecedented titles.

"My priority is the Champions League and to win everything that I can with Paris but the Champions League is our biggest objective."

The 25-year-old said he was "sad" that some believed he had moved to earn more money. His five-year contact is reportedly worth approximately $45 million a year before tax, making him the highest-paid player in the history of his sport, but the footballer said the sums associated with him did not make him feel uncomfortable.

"I'm just happy and flattered that they believe in my football and they brought me to a club as big as Paris," he said.

"I am not a guy who's motivated by money -- but by happiness and challenges."

Earlier, he had told a news conference: "What I think about is my happiness and together with my family, I want them to be happy.

"If I was following the money, I would be somewhere else, with other clubs in other countries.

"I'm really sad that people still think that way and I'm glad that PSG believe in me

"My heart told me to sign for PSG and I did it.

"It was one of the toughest decisions I ever took. I was at a great club at Barcelona, I love Barcelona, have friends at the club, some fantastic players, and it wasn't easy at all.

"I had to think, rethink about what I wanted to do and achieve in my life."

'An idol for sports lovers'

Photos: Neymar: The world's most expensive footballer After telling Barcelona he wanted to leave the club, Brazilian football star Neymar is heading to Paris Saint-Germain. PSG has activated his $263 million buyout clause, which is a world-record fee for a player transfer. Hide Caption 1 of 18 Photos: Neymar: The world's most expensive footballer Neymar fends off Japan's Takuya Okamoto during the U-17 World Cup in October 2009. Earlier that year, Neymar made his professional debut for Brazilian club Santos -- the same club that once fielded the legendary Pele. Hide Caption 2 of 18 Photos: Neymar: The world's most expensive footballer Neymar makes a heart gesture after scoring a goal for Santos in August 2010. That season, he scored 42 goals in all club competitions. Hide Caption 3 of 18 Photos: Neymar: The world's most expensive footballer Neymar celebrates after Santos won the Copa Libertadores in June 2011. It was the first time since 1963 that Santos had won the top club competition in South America. Hide Caption 4 of 18 Photos: Neymar: The world's most expensive footballer Neymar battles Argentina's Lionel Messi during an international friendly in June 2012. The two would later become teammates at Barcelona. Hide Caption 5 of 18 Photos: Neymar: The world's most expensive footballer Neymar holds his son, Davi Lucca, at a Santos match in May 2013. Hide Caption 6 of 18 Photos: Neymar: The world's most expensive footballer In June 2013, Neymar was unveiled as Barcelona's new star signing. Hide Caption 7 of 18 Photos: Neymar: The world's most expensive footballer Brazil was the host of the 2014 World Cup, but the tournament ended painfully for Neymar. He suffered a fractured vertebra in the quarterfinal victory against Colombia, and the Brazilians were trounced by Germany in the semifinals. Hide Caption 8 of 18 Photos: Neymar: The world's most expensive footballer Neymar lifts the trophy after Barcelona won the Champions League in June 2015. It completed a historic treble for the Spanish club, which also won the league and the Copa del Rey that season. Hide Caption 9 of 18 Photos: Neymar: The world's most expensive footballer From left, Messi, Neymar and Luis Suarez pose for a photo after Barcelona won the FIFA Club World Cup in December 2015. The three attacking players have been an imposing force together. Hide Caption 10 of 18 Photos: Neymar: The world's most expensive footballer Neymar competes with Germany's Sven Bender during the 2016 Olympic final in Rio de Janeiro. Neymar's goal in the penalty shootout clinched the gold medal for Brazil. Hide Caption 11 of 18 Photos: Neymar: The world's most expensive footballer Neymar and his Brazilian teammates show off their Olympic gold medals. Hide Caption 12 of 18 Photos: Neymar: The world's most expensive footballer Neymar celebrates a goal against Colombia during a World Cup qualifier in September 2016. He has scored more than 50 goals for his country's senior team. Hide Caption 13 of 18 Photos: Neymar: The world's most expensive footballer Since arriving to Barcelona in 2013, Neymar has helped the club win the Champions League, two league titles and three Copa del Reys. He has scored more than 100 goals. Hide Caption 14 of 18 Photos: Neymar: The world's most expensive footballer Neymar tries an overhead kick during a Spanish league match against Villarreal in May. Hide Caption 15 of 18 Photos: Neymar: The world's most expensive footballer Neymar sits next to another world-famous athlete -- Formula One champion Lewis Hamilton -- while attending Game 2 of the NBA Finals in June. Hide Caption 16 of 18 Photos: Neymar: The world's most expensive footballer A boy wearing Neymar's jersey walks past a new Barcelona poster -- without Neymar -- as it is put up outside the Camp Nou stadium on Wednesday, August 2. Hide Caption 17 of 18 Photos: Neymar: The world's most expensive footballer Neymar juggles a ball Friday, August 4, after he was unveiled to the media as Paris Saint-Germain's newest signing. His transfer fee was more than double the previous world record. Hide Caption 18 of 18

Club president Nasser Al-Khelaifi said Neymar was "an idol for the whole world for football lovers and sports lovers in general."

He added: "For me personally, Neymar is the best player in the world."

Al-Khelaifi also rejected claims the player had only joined PSG for financial reasons.

"Neymar came here for motivation, a project that he believed in," he said. "He can get much more money than we give him, that's for sure.

"If he came for money, he could go to other clubs for even more money."

Supporters of Paris-Saint-Germain's new signing Neymar pose with scarves outside the Paris-Saint-Germain (PSG) football club store.

After joining Barcelona from Brazilian club Santos in 2013, Neymar scored over 100 goals as well as winning the European Champions League, two La Liga titles and three Copa del Rey.

The 25-year-old was part of the world football's most potent attacking triumvirate alongside five-time world player of the year Lionel Messi, and Uruguay star Luis Suarez.

He has also scored 52 goals in 77 appearances for Brazil as well as winning Olympic gold at last year's Rio Games.

When asked if he was moving to escape Messi's shadow, Neymar said, "Messi is number one, for me, the best I've ever saw playing, and every player next to him is number two. I haven't come to Paris to be the first, to be number one. On the contrary, I came to help my teammates, to make history and to make history with this club."

Hundreds of PSG fans had lined up to purchase replica team jerseys with Neymar's name on earlier Friday.

The forward, who has signed a five-year deal with the club, will wear the No.10 shirt and could make his PSG debut against Amiens on Saturday.