Teen activist Greta Thunberg stares down Trump at UN summit

A video showing teenage climate activist Greta Thunberg staring down United States President Donald Trump has amassed millions of views on the social media.

In the video, Thunberg can be seen seen demonstrating her extreme displeasure at seeing US President Trump at a climate summit held in New York yesterday.

Trump appears not to have noticed Greta during his arrival, but later tweeted that she was a young girl with a bright future. Trump is often accused of being a climate change denier. 

Earlier on Monday, an emotional Greta Thunberg tore into world leaders at a UN climate summit Monday, accusing them of betraying her generation by failing to tackle greenhouse gas emissions, as announcements by major economies fell far short of expectations.

The Swedish teen's impassioned speech, in which she repeated the words "How dare you" four times, was the defining moment of the meeting, called by UN chief Antonio Guterres to reinvigorate the faltering Paris climate agreement.

Ahead of the conference, the United Nations issued a release saying 66 countries vowed to achieve carbon neutrality by 2050, along with 10 regions, 102 cities, and scores of businesses.