Teen climate activist Greta Thunberg squashed criticism from President Trump and Treasury Secretary Steve Mnuchin on the last day of the World Economic Forum on Friday, saying it's had "no effect" on her. She also took part in a climate march, days after calling for world and business leaders at the event to divest from fossil fuels.

Almost two years since her first school strike, Thunberg concluded her week in the Swiss Alps by participating in one of her signature climate action protests with other young people. During a news conference before the march with fellow youth leaders, Thunberg fielded a question from a reporter who asked about the effect Mr. Trump and Mnunchin has had on targeting her publicly. She said it's had "no effect" on her.

"If we care about that, we wouldn't be able to do what we do," she said. "We cannot care about those kinds of things. If we put ourselves in this spotlight, then we know that people do not understand the situation. The situation is not being treated as the crisis it is."

Swedish climate activist Greta Thunberg marches during a "Friday for the Future" youth demonstration in Davos, Switzerland. FABRICE COFFRINI/ Getty Images

She expressed frustration on lack of action from influential people at Davos in position to mitigate the climate change crisis.

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"We must remember that as long we do not treat this crisis as a crisis, and as long as facts and science are being left completely ignored, then we will not be able to solve this crisis," she said. "Before we came here, we had a few demands for this WEF and of course, those demands have been completely ignored. We expected nothing less."

"As long as the situation is not being treated as a crisis, then world and business leaders can continue to ignore the situations and don't have to do anything because they are not being held accountable," Thunberg added.

The strike caps off a newsworthy week for Thunberg. On Wednesday, she accused politicians of all stripes of making promises but failing to deliver any results, saying, "Our house is still on fire." She also demanded companies and governments divest from fossil fuels, as well as "immediately end all fossil fuel subsidies."

Mnuchin dismissed her remark and said she could explain it after "she goes and studies economics in college." Thunberg fired back on Twitter, as experts in the field, including a chief economist at Mnuchin's former employer, Goldman Sachs, touted the benefits of policies to fighting climate change and its positive impact on the global economy.

The activist has been criticized by Mr. Trump, who took a veiled swipe at her remarks when he spoke at Davos. Mr. Trump said it was time to reject the warnings of "prophets of doom and their predictions of the apocalypse."