Dont expect Greta Thunberg to meet with President Donald Trump anytime soon.

On The Ellen DeGeneres Show Friday, the 16-year-old Swedish climate activist said she didnt see much point in meeting with the president, who appeared to mock her on Twitter last month.

I dont understand why I would do that, Thunberg said. I dont see what I could tell him that he hasnt already heard, and I just think it would be a waste of time, really.

Though Thunbergs activism has garnered high-profile supporters, its also sparked ire from many conservatives. Most recently, her Sept. 23 speech at the United Nations Climate Action Summit was criticized by Fox News host Laura Ingraham , among others.

DeGeneres said she had been trying to book Thunberg as a guest on the show for two months. Not only does the teen have a packed schedule of climate rallies and conferences to attend, but she has also given up flying as part of her commitment to living a low-carbon life.

Elsewhere in the interview, Thunberg said she first learned about climate change in elementary school, when she was between the ages of 7 and 9.

I just couldnt believe it, because I thought if this was really true, then surely, someone mustve done something, Thunberg said. Then, surely, we would take it seriously. But no one took it seriously.

Once I fully understood, I couldnt just look away anymore, she added.

Thunbergs Ellen appearance coincides with her visit to Los Angeles , where she will be the keynote speaker at Fridays youth climate strike.