Washington CNN  — 

Michelle Obama offered a message of support to teen climate crisis activist Greta Thunberg, after the 16-year-old was mocked on Twitter by President Donald Trump.

“Don’t let anyone dim your light,” the former first lady wrote on Twitter Thursday to Thunberg. “Like the girls I’ve met in Vietnam and all over the world, you have so much to offer us all.”

Without mentioning Trump, the former first lady added, “Ignore the doubters and know that millions of people are cheering you on.”

Thunberg, who has inspired protesters worldwide to push for action in combating the climate crisis, was named Time magazine’s Person of the Year this week.

Trump on Thursday morning tweeted that it was “so ridiculous” for Thunberg to be recognized as Person of the Year.

“Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill!” Trump wrote.

Following the President’s tweet, Thunberg updated her Twitter bio to reflect Trump’s comments.

Democratic presidential frontrunner Joe Biden, who served as Barack Obama’s vice president, chastised Trump for his comments, writing on Twitter, “What kind of president bullies a teenager?”