Many of Thunberg's Twitter followers applauded her for her "last dig" towards Trump, including the former President's niece Mary Trump who replied to Thunberg's Twitter writing, "Well played."
"You've been Greta Thun-burned!"
It is safe to say the Thunberg and the former president have not seen eye to eye in the past few years.
Last November, she told Trump to "chill" after he labelled the US presidential election a "fraud" and that Joe Biden had not won fairly.
During this time, Trump often tweeted "Stop the Fraud" and "Stop the Vote".
"So ridiculous. Donald must work on his Anger Management problem, then go to a good old fashioned movie with a friend! Chill Donald, Chill" she said in response to his false claims.
The praise may sound familiar, that's because it was written by Trump himself when referring to Greta.
In response to the climate activist being TIME Magazine's Person of the Year in 2019, Trump said he didn't believe that she deserved the accolade.
He said she should "chill out" and work on her "anger management problem".
Following her speech at the UN Climate Summit, Trump shared a video captioning it: "She seems like a very happy young girl looking forward to a bright and wonderful future. So nice to see!"
In response Thunberg updated her Twitter bio to read: "A very happy young girl looking forward to a bright and wonderful future."
