Greta Thunberg responded to Donald Trump's criticism on Instagram. The former US president called the Swedish climate activist a "troublemaker" during a press conference.
Trump made his comments at the Oval Office on Monday evening. He suggested Thunberg needed medical help for her anger issues.
"She's a troublemaker who can't handle her anger," Trump told reporters. "I think she should see a doctor. She's a young person and so angry, she's nuts."
Thunberg replied with a brief Instagram post. She wrote, "I gratefully accept recommendations."
The exchange occurred after Thunberg's recent detention in Israel. She and hundreds of other activists attempted to break the Israeli blockade of Gaza.
Authorities held the activists before releasing them. Thunberg then traveled to Greece to continue her work.
Thunberg criticized governments for failing to protect humanitarian missions. She said they talk about human rights but provide no security for aid deliveries.
Political tensions often surface between climate activists and conservative leaders. This public spat shows how environmental advocacy remains politically divisive worldwide.