Speaking in the arrivals section of Paris' Charles de Gaulle airport after being deported from Israel, the Swedish activist said she and her team had broken no laws, and called for the immediate release of the activists still in Israel.
"I was very clear in my testimony that we were kidnapped on international waters and brought against our own will into Israel," she said.
She laughed off criticism from US President Donald Trump, who had described her as an angry person, saying: "I think the world needs a lot more young angry women to be honest, especially with everything going on right now."
Thunberg, 22, arrived in Paris a day after the Israeli navy prevented her and a group of fellow pro-Palestinian activists from sailing to the Gaza Strip.
Israeli forces boarded the charity vessel as it neared the Gaza Strip early on Monday, trying to break through a years-old naval blockade of the coastal enclave, and seized the 12-strong crew including Thunberg.
Thunberg denied her mission to deliver aid to the Gaza Strip by breaking through the naval blockade was a PR stunt, saying a previous effort in a larger boat was ended after the vessel was bombed.
She said she was now in desperate need of a shower and sleep.
She admitted it was unclear where she would be heading next, telling reporters it could be Sweden.
