At a meeting of the Senate climate crisis task force on Tuesday, lawmakers praised a group of young activists for their leadership and display of wisdom far beyond their years. They then asked the teenagers for advice on how Congress could combat climate change.
Thunberg, who has inspired young people across the world to demand more action to combat the impact of global warming, told the lawmakers that she was a student, not a scientist - or a senator.
"Please save your praise. We don't want it. Don't invite us here to just tell us how inspiring we are without actually doing anything about it because it doesn't lead to anything," she told the Senate climate task force, according to the BBC.
"If you want advice for what you should do, invite scientists, ask scientists for their expertise. We don't want to be heard. We want the science to be heard.
"I know you are trying, but just not hard enough. Sorry," the climate activist told the US Congress.
Senator Ed Markey, who led the climate team, ignored Thunberg's advice not to praise her, describing her as a "superpower".
"You put a spotlight on this issue in a way that it has never been before. And that is creating a new X factor," he said.
Instead of submitting a personal statement, she sent Congress a major report on global warming along with eight sentences of her own.
"I am submitting this report as my testimony because I don't want you to listen to me," she said. "I want you to listen to the scientists. And I want you to unite behind the science. And then I want you to take action."
During her visit to the US capital, the teen activist also met former President Barack Obama who called her "one of our planet's greatest advocates".
Greta's appearance in front of US politic comes ahead of planned climate strikes around the world on Friday. There will be 4,638 events in 139 countries, according to the Swedish activist. A further strike is planned for the following Friday.
She will testify in the US Congress on Wednesday before heading to New York for the climate strike, and addressing the UN Climate Action Summit next week.
( With inputs from IANS )