North Korea could possess 100 nuclear weapons by 2020, warn US researchers

Analysts also called on the international community to 'wake up' to the possible threat from the Hermit Kingdom

Kim Jong-un, pictured last year with his generals, has incited increasing global unease over his nuclear tests (AFP)

North Korea could significantly expand its arsenal by up to 100 atomic arms by 2020, top US researchers have claimed amid calls for the international community to “wake up” to the threat.

Analysts at the US-Korea Institute at Johns Hopkins University said that North Korean scientists have succeeded in miniaturising nuclear warheads, allowing them to be fitted to longer-range ballistic missiles.

Joel Wit, the chief analyst of respected website 38 North, gave a seminar in Washington yesterday outlining his three main predictions for the isolated dictatorship.

The prediction of 100 missiles was a “worst case scenario”, Mr Witt said.

South Korean passengers watch TV news reporting North Korea's apparent nuclear test (Getty Images)

These weapons may have a yield of as much as 50 kilotons, analysts believe. The atomic bomb dropped on Hiroshima in 1945 had a yield of 18 kilotons.

Based on North Korea’s current trajectory, it is more likely that the country would see a moderate growth in the stockpile, which would see the nuclear arsenal expand to 50 weapons by 2020.

An annotated satellite photo indicating signs of new activity at the 5 MWe Plutonium Production Reactor at North Korea's Nyongbyon Nuclear Scientific Research Center (AP)

With minimal growth, the Hermit Kingdom may only expand its arsenal to 20 weapons.

However, Mr Wit said that not only are North Korean scientists believed to have developed the ability to place nuclear warheads inside smaller missiles – thus enabling them to reach much further – he added that the country can expand its nuclear range without additional tests.

North Korea has already carried out three underground nuclear tests, the most recent (and powerful) in January last year, watched by the West with increasing alarm.

"Even as we are sitting here, I'm willing to bet they're producing fissile material for nuclear weapons even though they haven't conducted a test," Mr Wit was quoted by Yonhap news as telling the seminar.

The worst case scenario could occur should significant technical advances achieved. These would allow Pyongyang to overcome (among other problems) the intricate difficulties of launching a nuclear rocket capable of surviving the exit and re-entre flight.