Russia’s foreign minister warned on Monday that the risk of nuclear war is “considerable” and should not be underestimated while accusing NATO of engaging in a proxy war against Russia by arming Ukraine.

In an interview with state television, Russian Foreign Minister Sergey Lavrov claimed that Russia has been striving to avoid a nuclear conflict since its Feb. 24 invasion of Ukraine, but he said communication with the United States has “practically ceased” and that the Ukrainian side is not negotiating for peace in good faith.