Teenage climate change activist Greta Thunberg said Monday that talking to U.S. President Donald Trump at a United Nations summit on global warming would have been a waste of time since he would not have paid any attention.

In an interview with BBC radio’s "Today" program, for which she was the guest editor Monday, Thunberg also said she regarded personal attacks on her as funny and that she hoped to go back to having a normal life.

A video of the 16-year-old Swedish campaigner giving Trump what media described as a "death stare" at a U.N. climate summit in New York in September went viral on social media. Trump has questioned climate science and is pulling the United States out of the 2015 Paris Agrement on global warming.