North Korea’s U.N. ambassador warned the United States and the rest of the world Wednesday that his country will keep building up its nuclear arsenal regardless of sanctions, pressure or military attack.

Kim In Ryong told the U.N. Security Council that the more than 50-year confrontation between North Korea and the United States came closer to the brink of nuclear war than ever before when the U.S. military held what he called its largest-ever “aggressive” maneuvers with South Korea in April and May.

Since then, he said, the United States has sent B-1B nuclear bombers into South Korean airspace, deployed the THAAD anti-missile system in the country, imposed new U.S. sanctions against North Korea, and spearheaded another U.N. sanctions resolution.

Kim said the Trump administration is pursuing an outdated “hostile policy” toward the Democratic People’s Republic of Korea, which is North Korea’s official name.

He said the United States is modernizing its nuclear weapons but other countries aren’t allowed “to test or launch any object which goes with the words of nuclear or ballistic.”

“This is really the height of shameless arrogance, self-righteousness and double standards,” he said.

Accusing the U.S. of trying to hold down North Korea and retain a military edge in Asia as part of “its dream of world domination,” Kim said the North Korean people have concluded that to defend their rights and sovereignty they must respond in kind.

“No matter what others say, whatever sanctions, pressure and military attack may follow, we will not flinch from the road to build up nuclear forces, which was chosen to defend the sovereignty of the country and the rights to national existence,” he said.

The North Korean ambassador was making a rare appearance in the Security Council at an open meeting on implementation of a resolution adopted in 2004 aimed at keeping terrorists, extremists and other “non-state actors” from obtaining nuclear, chemical or biological weapons. He has boycotted council meetings dealing with U.N. sanctions against North Korea.

A statement read at the council meeting by Spain’s U.N. ambassador, Roman Oyarzun Marchesi, on behalf of 51 countries that strongly oppose the spread of weapons of mass destruction condemns “proliferation in all possible forms by anyone” — and vows to “make every effort to prevent it.”

“In this connection, we condemn in the strongest terms the nuclear weapons and ballistic missile development activities conducted by the DPRK in flagrant violation of the Security Council’s resolutions,” said the statement, whose signatories include the United States and countries from Asia, Africa, the Mideast, Latin America and Europe.

The U.N. disarmament chief, Izumi Nakamitsu, warned the Security Council that advancements in science and technology in an increasingly interconnected world are making it more difficult to prevent “the disastrous scenario” of terrorists using nuclear, chemical and biological weapons. She said that while globalization brings new opportunities for economic growth and development it also facilitates the rapid movement of materials and the latest scientific and technological discoveries as well as people with expertise.

“Non-state actors including terrorist organizations will exploit any loophole to obtain these technologies,” she said.

“While there are still significant technical hurdles that terrorist groups need to overcome to effectively use weapons of mass destruction, a growing number of emerging technologies could make this barrier easier to cross,” Nakamitsu said.

She pointed to the use of drones, 3D printers and the exploitation of “dark web” as a marketplace to buy dual-use equipment and materials.

“Dual use is further complicating our efforts to address the risk posed by the proliferation of weapons of mass destruction,” Nakamitsu said.

(AP)