Czech President Milos Zeman called for international military action led by the United Nations Security Council against global terrorism.

Comparing Islamic State to Nazi Germany in the 1930s, Zeman said the group represents today’s biggest security threat. It has the potential to carry out a “super-holocaust” resulting in hundreds of millions of deaths, the Czech president said during a speech on Tuesday at a Holocaust commemorative event in Prague.

At the very least, all members of the UN Security Council should deploy troops to tackle terrorist groups by using modern military technology, Zeman said.