US Treasury Secretary Steven Mnuchin has told Greta Thunberg to get an economics degree before advising world leaders how to deal with climate change.
Greta, 17, has visited a number of countries recently to raise awareness of the threat posed to the world by the changing climate.
Among those she has criticised is Donald Trump, particularly over his decision to pull the US out of the Paris agreement signed in 2016 by almost 200 countries to limit global warming.
At the World Economic Forum in the Swiss town of Davos, Mr Mnuchin responded to the teenager’s call for a move away from fossil fuels.
When asked how such a move would affect the US economy, he said: “Is she the chief economist? Who is she? I’m confused.”
Then following a brief pause, he said: “It was a joke.
“After she goes and studies economics in college, she can come back and explain that to us.”
More from Business
Lloyds to write off debts worth tens of millions linked to HBOS fraud
Morrisons creating 7,000 shop-floor jobs – but 3,000 managers will go
China’s markets suffer biggest fall in months as virus fears grow
Jack’s Law: Paid bereavement leave for parents who lose a child starts in April
Almost 60,000 retail jobs were lost last year
Eurotunnel operator blames Brexit for revenue hit
Mr Mnuchin insisted that Mr Trump “absolutely believes” in a clean environment and that the country has been a leader in reducing carbon emissions.
He added: “What the president objects to is the Paris agreement, because he thought it was an unfair agreement for the United States.”
Mr Trump, who has also been at Davos, called climate activists such as Greta “prophets of doom” on Tuesday, following previous criticism of her, including saying she needs “anger management”.
But on Wednesday he promised to join a plan to plant more trees.
During her speech at Davos, Greta told world leaders that “our house is still on fire” and that their “inaction is fuelling the flames”.
She described their assurances as “empty words and promises”.
Some business leaders suggested they were trying to move Mr Trump towards a middle-ground on climate policy.
Regarding the tree-planting vow, Salesforce chief executive Marc Benioff said “many people” were involved in convincing the US president to join the initiative.
Joe Kaeser, the chief executive of German company Siemens, said he had told Mr Trump to listen to the young activists, adding: “We have to sit together and involve them in dialogue”.
Mr Trump told reporters he no longer considered climate change a hoax but he added: “You have another continent where the fumes are rising at levels that you can’t believe… I think Greta ought to focus on those places.”