The US, Mnuchin said, has been a leader in reducing carbon emissions.
And just two days later, Mnuchin's own wife appeared to take Thunberg's side.
Diversification is crucial to ensuring a country's security in the rollout of 5G mobile technology and shunning one supplier altogether risks being counterproductive, German Chancellor Angela Merkel said.
In her speech to the forum, Merkel said that older politicians had to use the "positive manner and constructive impatience of young people", who she said "have a completely different horizon" in terms of time. "Who is she? I'm confused", Mnuchin said.
Mr Mnuchin added President Donald Trump had previously said the United Kingdom would "be at the top of the list" for a deal.
Annabella Sciorra says Harvey Weinstein brutally raped her
The producer allegedly raped her again the following November, when she agreed to cut Weinstein's hair in another hotel room. She finally came forward with her allegations in 2017 as part of The New Yorker's exposé on Weinstein .
Her parents, hesitant at first, are now supportive and Axelsson says her grades have improved, allowing her to finish high school and start studying human geography at university.
"We are being criticized like that all the time", Thunberg said at the news conference onstage with four other campaigners. "Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend!"
In response to Mnuchin's comment on Thursday, Thunberg tweeted a graph from a United Nations report showing how the world's remaining carbon budget will be depleted by 2027 unless global emissions are curbed. "Now chilling and watching a good old fashioned movie with a friend".
But Thunberg, who was reportedly in attendance during Trump's speech, maintained Tuesday that she has no interest in political tiffs.
"If we cared about that, we would not be able to do what we do".
Sustainability was the topic of scores of panels, meetings and cocktail conversations in Davos, where attendees and the media discussed the implications of recent announcements such as Microsoft's plan to go "carbon negative" by 2030 and Blackrock's commitment to put the issue at the heart of its investment strategy.