The climate change activist was at the UN Climate Action Summit in New York.

Greta Thunberg’s glare as she laid eyes on Donald Trump at a climate change summit has gone viral.

The 16-year-old activist was at the UN Climate Action Summit in New York on Monday, where she delivered an impassioned speech to delegates urging them to take action to tackle rising temperatures.

But she also gained attention for her reaction when the US president walked past her, as she appeared to aim a glare in his direction.

The moment caught the eye of people watching, with many praising the teenager.

Twitter user Dr Lauren Gavaghan wrote: “The image of Trump, a grown man, swaggering into UN climate summit, swinging his arms & throwing his weight around, in stark contrast to a dignified 16 yr old Greta Thunberg standing behind him, but with a strength that puts him to shame, is a reminder of how wrong this all is.”

Sean O’Regan added: “Has there ever been more of a death stare than this from Greta Thunberg to Donald Trump?”

Mr Trump himself later responded to the speech from Ms Thunberg, in which she said: “You come to us young people for hope – how dare you? You have stolen my dreams, my childhood with your empty words.”

In a tweet, Mr Trump said: “She seems like a very happy young girl looking forward to a bright and wonderful future. So nice to see!”