US Secretary of State Antony Blinken said Friday that Russian forces “are increasingly using brutal methods in Ukraine, including going at civilian populations.”

His comments followed a Russian attack on a Ukrainian nuclear plant — the largest facility of its kind in Europe — that had sparked a fire in a building at the plant compound.

Speaking to reporters before a meeting with his European Union counterparts in Brussels, Blinken said, “We are faced together with what is [Russian] President [Vladimir] Putin’s war of choice: unprovoked, unjustified, and a war that is having horrific, horrific consequences.”

“We’re committed to doing everything we can to make it stop,” he added, but ruled out imposing a no-fly zone over Ukraine, saying such an action could lead to a broader conflict.

“We have a responsibility to ensure the war does not spill over beyond Ukraine. … A no-fly zone could lead to a full-fledged war in Europe,” he said.

The meeting in Brussels came after Ukraine accused Russia of “nuclear terror” for shelling and starting a fire at the Zaporizhzhia nuclear plant before taking control of it. The plant is in the city of Enerhodar, in the country’s southeast.

Ukraine’s nuclear inspectorate said that no radiation had leaked at the plant and that personnel were continuing to operate the facility safely. Firefighters were able to get the blaze under control, Ukrainian officials said.