Russian President Vladimir Putin says Moscow has tested a new intermediate-range missile in a strike on Ukraine and that it could use the weapon against countries that have allowed Kyiv to use their missiles to strike Russia.

Ukrainian President Volodymyr Zelenskyy said Thursday that his “insane neighbor” is once again showing the world its true nature, “its disdain for dignity, freedom, and human life itself.

The attack with an intermediate-range ballistic missile has spurred fears of a major escalation in the ongoing war and prompted Ukraine to request new air defenses.