Michelle Obama defends Greta Thunberg: 'Ignore the doubters'

Michelle Obama has come to the defence of 16-year-old Swedish climate-change activist Greta Thunberg after US President Donald Trump mocked her for being named the New York Times' Person of the Year.

The former US first lady recently took to social media to offer words of encouragement to Thunberg, tweeting: “Don’t let anyone dim your light.”

This was after Trump called Thunberg's Time accolade “so ridiculous”. He also insinuated that she had mental health problems and said she needed to “chill”.

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

This is not the first time Trump has mocked the teenage activist.

She has hit back at him too. In September, Thunberg shot back at Trump's attempt to mock her on Twitter by changing her profile on the social media site to reflect his remark after he sarcastically called her a “happy young girl”.

Obama’s post saw many telling Trump to back off and stop picking on the girl.