The 16-year-old shot the U.S. president a death stare as he passed her at U.N. headquarters in New York, and the moment was caught on camera.

Teen climate activist Greta Thunberg said it all with her eyes when she saw President Donald Trump at the United Nations Climate Action Summit on Monday.

The Swedish teen, who sailed to New York on a zero-emissions yacht to avoid the environmentally costly repercussions of flying, said before her departure that she had no plans to speak to Trump during her time in the U.S.

“Why should I waste time talking to him when he, of course, is not going to listen to me?” Thunberg told CBS in August. “I can’t say anything that he hasn’t already heard.”

She told a reporter that her message to Trump would be to “just to listen to the science,” adding that he “obviously doesn’t do that.”

On Monday, Thunberg delivered a fierce rebuke to world leaders at the U.N. summit, condemning them for prioritizing “money and fairy tales of eternal economic growth” over the fate of the planet.

The U.S. president, who had not been slated to attend the summit, appeared for 10 to 15 minutes at the event, listening to remarks by Indian Prime Minister Narendra Modi and German Chancellor Angela Merkel, The Hill reported.

Twitter users were quick to pounce on the moment Trump walked past Thunberg, and the GIFs, memes and commentary flowed freely: