A South Korean man watches a TV news program showing North Korean leader Kim Jong Un at Seoul Railway Station in Seoul, South Korea, on Friday.
A South Korean man watches a TV news program showing North Korean leader Kim Jong Un at Seoul Railway Station in Seoul, South Korea, on Friday. Credit: AP Photo

WASHINGTON — President Barack Obama called North Korea’s latest nuclear test a “grave threat” to regional security and international stability and again vowed to take “additional significant steps,” including sanctions, against the rogue state.

North Korea’s fifth test, which South Korean officials called its most powerful to date, shows that it has no interest “in being a responsible member of the international community,” Obama said Friday. The president reiterated that the U.S. “does not, and never will, accept North Korea as a nuclear state.”

The latest North Korean test occurred as the president was returning from a trip to Asia that included a bilateral meeting with South Korean President Park Geun-hye. He was briefed about the detonation aboard Air Force One en route to Washington, and spoke again with Park and Japanese Prime Minister Shinzo Abe in separate calls from the presidential aircraft.

North Korea’s aggressive ballistic missile tests that preceded the nuclear test, which took place as Obama joined Asian leaders for a regional summit in Laos and after the G-20 Summit in China, had already led Obama to seek more effective sanctions from the United Nations.

At a news conference Thursday, Obama said that persuading Pyongyang to change its behavior has been difficult. Not only has it failed to meet its international obligations, but there was no indication North Korea was inclined to do so soon, he said.

“We are going to make sure that we put our defensive measures in place so that America is protected, our allies are protected. We will continue to put some of the toughest pressure that North Korea has ever been under as a consequence of this behavior,” he said. “Can I guarantee that it works? No. But it is the best options that we have available to us right now.”