Russia has threatened to deploy nuclear weapons in and around the Baltic Sea region if Finland and Sweden join NATO as tensions fueled by Vladimir Putin’s invasion of Ukraine spread.

"In this case, there can be no talk of non-nuclear status for the Baltic,” Dmitry Medvedev, deputy chief of the Security Council and former president, said in a Telegram post Thursday, suggesting Russia may deploy Iskander missiles, hypersonic weapons and nuclear-armed ships in the region.

Medvedev’s comments are among the most detailed threats Russia has issued over the prospect that its northwestern neighbors might join the alliance after decades of staying out. But both Finland and Sweden this week said they’re stepping up consideration of the issue in the wake of Russia’s invasion of Ukraine.