The state-run Korean Central News Agency on Friday confirmed that North Korea successfully conducted its most powerful nuclear test yet, with an explosion that several countries marked as a 5.3-magnitude seismic event. “This has definitely put on a higher level [the North’s] technology of mounting nuclear warheads on ballistic rockets,” the outlet reported, touting the test as a breakthrough for Pyongyang. “The standardization of the nuclear warhead will enable [North Korea] to produce at will and as many as it wants a variety of smaller, lighter, and diversified nuclear warheads of higher strike power.” Yukiya Amano, head of the International Atomic Energy Agency, called the test “deeply troubling.” In a statement, Amano said, “This is in clear violation of numerous UN Security Council resolutions and in complete disregard of the repeated demands of the international community.” French Foreign Minister Jean-Marc Ayrault called Friday’s test a “serious act which infringes the world’s peace and security.” He added, “This escalation is unacceptable.”