Ukraine called for an emergency meeting of the U.N. Security Council Sunday as NATO condemned Russia for its “dangerous and irresponsible” suggestion it could soon deploy tactical nuclear weapons to Belarus. President Vladimir Putin made the comments Saturday.

President Vladimir Putin: “Alexander Lukashenko is right. He says, 'Listen, we're your closest allies.’ Why do the Americans deploy their nuclear weapons to their allies, on their territory, train the crews, pilots how to use this type of weapon, if needed? We agree that we will do the same.”

The head of the U.N.’s nuclear watchdog, Rafael Grossi, is due to visit the Russian-occupied Zaporizhzhia nuclear power plant this week amid ongoing fears over a possible nuclear disaster. The plant has had to rely on its emergency diesel generators six times over the past year due to attacks in the region.

On the battlefield, the Russian mercenary Wagner Group said it captured a metal plant in the north of Bakhmut. This comes after Ukraine said its military is still holding on to the decimated eastern city, which has been the site of some of the war’s fiercest battles for months.