A U.S.-organized U.N. event on North Korea's human rights briefly turned chaotic Thursday as North Korean diplomats insisted on reading a statement, amid shouts from defectors, and then stormed out of a United Nations chamber.

The U.S. ambassador to the U.N., Samantha Power, tried to quiet the North Korean diplomats at the event that featured more than 20 defectors.

The North Korean diplomats did not comment as they left the chamber after reading out a statement in protest of the event, even as North Korean defectors stood and shouted in their faces. Nuclear-armed North Korea has been on the defensive ever since a groundbreaking U.N. commission of inquiry detailed vast rights abuses there. International pressure behind last year's report led the U.N. Security Council to place the issue on its agenda of matters of international peace and security.

Defectors stood up and shouted in Korean as Power and others called for calm and a U.N. security team assembled. A microphone was briefly turned on.

"There is no need for a microphone," Power said as one North Korean diplomat persisted in reading out a statement that referred to "ungrounded allegations" and "hostile policy" toward his country.

As soon as the next featured defector, Jay Jo, started speaking, the North Korean diplomats stood and walked out.

The brief chaos came minutes after U.N. Assistant Secretary-General for Human Rights Ivan Simonovic told the audience that North Korea had shown "new signs of engagement" on human rights issues in recent months.

But after the uproar, South Korean Ambassador Oh Joon told the crowd that "we thought there was a glimmer of hope ... but the delegation of the DPRK today disappointed us. I think it's a pity." He was referring to the country's official name, the Democratic People's Republic of Korea."