Seoul, September 3
North Korea said it detonated a hydrogen bomb designed for a long-range missile today and called its sixth and most powerful nuclear test a “perfect success”, sparking global condemnation and promises of tougher US sanctions.

Pyongyang residents threw their arms aloft in triumph as a jubilant television newsreader hailed the “unprecedentedly large” blast. It “marked a very significant occasion in attaining the final goal of completing the state nuclear force”, she added.

But world reaction was swift and angry. US President Donald Trump said on Twitter Pyongyang’s “words and actions continue to be very hostile and dangerous to the United States”. The US Treasury Department will prepare sanctions that would “cut off North Korea economically”, said Treasury Secretary Steven Mnuchin.

Hours before the test, the North had released images of leader Kim Jong-Un at the Nuclear Weapons Institute, inspecting what it said was a miniaturised H-bomb that could be fitted onto an intercontinental ballistic missile (ICBM). China, the North’s sole remaining major ally, issued a “strong condemnation” of the test, which overshadowed the opening of the BRICS summit in Xiamen.

Japanese Prime Minister Shinzo Abe described it as “absolutely unacceptable”, while Russia’s foreign ministry expressed “strongest condemnation” but urged calm. In Seoul, President Moon Jae-In called for new United Nations sanctions to “completely isolate North Korea” and said the South would discuss deploying “the strongest strategic assets of the US military”.

That could be taken as a reference to tactical nuclear weapons, which were withdrawn from South Korea by Washington in 1991.

US monitors measured a 6.3-magnitude tremor near the North’s main testing site, which South Korean experts said was five to six times stronger than the 10-kiloton test carried out a year ago.

The tremor was felt in northeastern China, with people in the border city of Yanji saying they fled their homes in their underwear, and in the Russian Pacific city of Vladivostok. It was even detected as far away as Germany.

Whatever the final figure for the test’s yield, said Jeffrey Lewis of the armscontrolwonk website, it was “a staged thermonuclear weapon” which represents a significant advance.