European Union (E.U.) foreign policy chief Josep Borrell apologised Saturday for mildly critical comments he made about youth climate activists in general and Greta Thunberg in particular, in a very public display of contrition just a few months into his role.

“The idea that young people are seriously committed to stopping climate change — we could call it Greta syndrome — permit me my doubts,” Borrell, a 72-year-old Spanish socialist, said in reference to Greta Thunberg, the teenage Swedish climate worrier. “It is fine to demonstrate against climate change so long as nobody asks you to pay for it.

“I wonder if the young people demonstrating on the streets of Berlin to call for measures against climate change are aware of the costs of those measures — and if they are willing to reduce their living standards to compensate Polish miners.”

Borrell’s remarks were made at a European Parliament event Wednesday, and footage was widely circulated on social media on Friday, as the Financial Times reported.

The criticism came just as quickly as Borrell was widely denounced by Green activists for his opinions:

The comments of the High Representative of the EU @JosepBorrellF on the youth movements for climate are unacceptable for a representative of the EU. We’ll be asking for a full explanation from him next week.#fridaysforfuture #climatestrike #climatecrisispic.twitter.com/k9wLAMIkm0 — Greens/EFA in the EU Parliament (@GreensEFA) February 7, 2020

Now he has reversed his position and “clarified his thinking” on the matter.

“I want to apologise to anyone that may have felt offended by my inappropriate reference to the important youth movement fighting #climatechange,”Borrell wrote on Twitter while flying home from a visit to the U.S.

“Climate change is one of (the) biggest geopolitical challenges, we can’t afford costs of inaction,” he added, while noting that “to be successful, we also need to tackle social and economic costs of the transition.”

Just coming back from US trip, and I want to apologise to anyone that may have felt offended by my inappropriate reference to the important youth movement fighting #climatechange — Josep Borrell Fontelles (@JosepBorrellF) February 8, 2020

Youth movements to fight #ClimateChange have my full support and inspire politicians & societies. Climate change is one of biggest geopolitical challenges, we can’t afford costs of inaction. (1) — Josep Borrell Fontelles (@JosepBorrellF) February 7, 2020

Borrell’s reversal came after the Green group in the European Parliament denounced his opinions on Friday as, “unacceptable for a representative of the E.U.”

Carles Puigdemont, former Catalan regional president and now MEP, said on Twitter he had sent a formal letter to the European Commission, asking whether Borrell’s remarks on young climate change activists “are the official opinion of the Commission on the issue?” Puigdemont also asked how such views fit with the E.U.’s new Green Deal plan.

The European Commission has promised to spend billions of taxpayer euros a year towards its Green Deal with the goal of making the E.U. climate neutral by 2050.

Borrell will now have to explain himself and his thinking in front of the European Commission, as European Greens said they will, “be asking for a full explanation from him next week.”

The veteran politician is no stranger to controversy.

Last year he said the E.U. needs a standing army of 60,000 soldiers that Brussels can deploy around the world.

Borrell told at a European Parliament inquiry: “The European Union has to learn to use the language of power.”

He called for Brussels to raise the number of troops to at least 55,000 to 60,000. Such a force would be larger than the standing armies of Portugal (35,000) or the Netherlands (43,000).

“We should pull our national sovereignties together to multiply the power of individual member states. And I am convinced that if we don’t act together, Europe will become irrelevant in the new coming world,” he added.

AFP contributed to this story