Secretary of State Rex Tillerson called for an aggressive new set diplomatic and economic sanctions on North Korea in a Friday speech to the United Nations, in which he also said North Korea presents a real risk of nuclear war.

“Failing to act now on the most pressing security issue in the world may bring catastrophic consequences,” Tillerson said at a meeting of the UN Security Council. “Additional patience will only mean acceptance of a nuclear North Korea. The more we bide our time, the sooner we will run out of it.”