The 27-year-old has been jeered by many PSG fans this season after a failed bid to return to his former club Barcelona in the European summer, reports Xinhua news agency.
But he has responded with four goals in five league matches so far, including late winners against Lyon and Bordeaux in September.
"I'm happy in the national team and with my club too," Neymar told reporters on Wednesday ahead of Brazil's friendly against Senegal.
"Everyone knows what happened during the last transfer window, my initial desires, but today I'm happy and I feel comfortable in my club. The season has started well for me. I'm going to defend my club tooth and nail. I will give 100 per cent so that we can do great things."
Neymar is currently the third highest scorer in Brazil's history, having netted 61 times in 99 games. He is just one goal behind two-time World Cup-winner Ronaldo and 16 shy of record holder and three-time world champion Pele.
During Wednesday's press conference, Brazilian Football Confederation officials presented Neymar with a national team shirt adorned with the number 100 on its back to mark his milestone.
The former Santos prodigy said he has learned to cope with a rollercoaster of emotions throughout his international career, having been a part of Brazil's disappointing World Cup campaigns in 2014 and 2018, and winning an Olympic gold medal in Rio de Janeiro in 2016.
"There is a positive balance, but it isn't all about victories in the life of an athlete," Neymar said. "There are many disappointments, defeats and mistakes. But if you fight for it, in the end, you make up for your mistakes. I am very happy to reach that mark of 100 matches. Not even in my best dreams I thought this could happen."
Thursday's clash at the Singapore National Stadium will be followed by another friendly between Brazil and Nigeria at the same venue on Sunday.
( With inputs from IANS )