U.S. president Donald Trump doesn’t like the fact that teen climate activist Greta Thunberg has been named TIME’s Person of the Year, sending a disdainful and mocking tweet on Thursday morning that advised the 16-year-old to “work on her anger management” and “chill.”

Responding to a tweet congratulating Thunberg for the honour, Trump called it “so ridiculous” and suggested that Thunberg go to a movie with a friend instead of railing against global warming.

So ridiculous. Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill! https://t.co/M8ZtS8okzE — Donald J. Trump (@realDonaldTrump) December 12, 2019

Thunberg was quick to respond, changing her Twitter bio to: “A teenager working on her anger management problem. Currently chilling and watching a good old fashioned movie with a friend.”

Trump’s son, Donald Trump Jr., also tweeted his disapproval, suggesting that Hong Kong protesters should have been given the nod by TIME Magazine.

In a tweet, Trump Jr. accused TIME of promoting a “teen being used as a marketing gimmick.”

“How dare you?” he asked indignantly.

Time leaves out the Hong Kong Protesters fighting for their lives and freedoms to push a teen being used as a marketing gimmick. How dare you? https://t.co/dnV9mESM6G — Donald Trump Jr. (@DonaldJTrumpJr) December 11, 2019

President Trump isn’t the only world leader to speak out against Thunberg.

Brazilian President Jair Bolsonaro reportedly called her a “brat” on Thursday.

“Greta said that the Indians died because they were defending the Amazon,” Bolsonaro told a group of journalists according to the Associated Press. “It’s impressive that the press is giving space to a brat like that,” he added, using the Portuguese word ”pirralha.”

Thunberg has become the face of the youth climate movement, drawing large crowds with her appearances at protests and conferences over the past year and a half.

Some have welcomed her activism, including her speeches challenging world leaders to do more to stop global warming. But others have criticized her sometimes combative tone.

“For sounding the alarm about humanity’s predatory relationship with the only home we have, for bringing to a fragmented world a voice that transcends backgrounds and borders, for showing us all what it might look like when a new generation leads, Greta Thunberg is TIME’s 2019 Person of the Year,” the media franchise said Wednesday on its website.