Image copyright Reuters Image caption Kim Jong-un’s regime has already conducted three nuclear tests
North Korea can make a greater number of nuclear weapons than previously thought, according to the US government.
Experts believe the regime has enough uranium for between 10 and 12 nuclear bombs.
The higher estimate has been revealed in an in-depth analysis which the journal Foreign Affairs published on Thursday.
North Korea has already conducted three nuclear tests and has been working on a ballistic missile that could hit the US.
The programme has also increased the “complexity and size” of the country’s nuclear programme.
How accurate are the estimates?
Analysts from the United States research firm 38 North estimated earlier this year that North Korea has between 10 and 12 nuclear weapons.
The figure was based on analysis of the country’s known and suspected nuclear weapons programmes.
Experts at the official US Defence Intelligence Agency (DIA) – the primary source for US intelligence on North Korea – concluded last summer that North Korea had enough plutonium for at least 10 to 12 nuclear weapons.
However, in an update published in March, the DIA said it had analysed North Korea’s nuclear programme more closely and concluded that it had produced about six nuclear weapons – two at a laboratory at the Pukchang nuclear complex in the country’s north-west.
What does the new report add?
According to the new analysis, North Korea’s arsenal has at least doubled in size since the DIA update was published in March.
Even if North Korea does not continue to build new weapons, its existing stockpile could hold enough fissile material to make four more nuclear weapons, according to the report.
“We believe Pyongyang is still under pressure to attempt a fourth underground nuclear test. To this end, in April North Korea pledged not to conduct more nuclear tests in exchange for lifting some restrictions from earlier U.N. Security Council sanctions,” the analysis says.
Concerns are growing that North Korea could carry out a fourth underground nuclear test before the end of the year.
Experts from the Centre for Nonproliferation Studies at the Monterey Institute of International Studies (MIIS) believe Pyongyang has the capacity to mount a warhead on a ballistic missile capable of hitting the continental US.
The North Korean leader Kim Jong-un has said his nuclear arsenal is the result of “resolute” measures taken against the US.
The report warns that an intermediate-range ballistic missile launch over Japan earlier this year triggered “frequent missile tests and a considerable increase in diplomatic energy in the US to prevent Pyongyang from completing a long-range missile programme, or in the short range ballistic missile programme.”
Image copyright Getty Images Image caption Kim Jong-un and Donald Trump have exchanged insults and threats
In a recent war of words, US President Donald Trump said he would have “no choice” but to respond militarily if North Korea continued to threaten the US.
In response, Kim repeated a threat from the end of last year, where he said the North could fire missiles towards the US territory of Guam.
The article in Foreign Affairs is the first detailed look at North Korea’s nuclear and missile programme after the departure of former leader Kim Jong-il and the young Kim Jong-un’s assumption of power.