Swedish climate activist Greta Thunberg visited Kyiv on Thursday to draw attention to environmental damage caused by war in Ukraine and criticized the world’s response to the June 6 collapse of the vast hydro-electric Kakhovka dam.

Ukraine is investigating the dam blast, which unleashed floods across southern Ukraine and Russian-occupied areas of the Kherson region, as a war crime and possible criminal environmental destruction, or “ecocide”. It has estimated the cost of the dam’s collapse at 1.2 billion euros.

Kyiv and Russia have blamed each other for the dam’s destruction.

“I do not think that the world reaction to this ecocide was enough,” said Thunberg, who was in Kyiv for the inaugural meeting of a new environmental group that also includes senior European political figures.

“We have to talk louder about it, we have to raise awareness about what is going on,” she said, according to a Ukrainian translation of her comments.

The group is tasked with assessing the damage to Ukraine’s environment and developing mechanisms to hold Russia accountable, said Andriy Yermak, head of the Ukrainian presidential staff and co-chair of the group along with former Swedish deputy prime minister Margot Wallstrom.

The environment risks becoming the “silent victim of war” with about 30% of Ukraine’s territory contaminated with explosive objects and over 2.4 million hectares of forests damaged, Ukraine’s prosecutor general Andriy Kostin said in a Twitter post to mark the meeting.

“We call for strengthening international efforts to investigate and prosecute Russia’s war crimes against the environment and to ensure that the aggressor pays,” he said.

President Volodymyr Zelenskiy attended the meeting and thanked members of the group for their visit as an “extremely important signal of support.”