North Korea has developed miniaturized nuclear warheads that could be installed inside its missiles, taking an additional step towards becoming a nuclear power, U.S. intelligence officials have concluded.
The confidential conclusion by the Defense Intelligence Agency says the U.S. intelligence community has concluded "North Korea has produced nuclear weapons for ballistic missile delivery, to include delivery by [intercontinental ballistic misile]-class missiles," the Washington Post on Tuesday quoted the assessment as saying.
Miniaturization is the process necessary to harness a missile with a nuclear warhead. These developments follow North Korea's tests last month, proving the country's ability to reach intercontinental ranges.
A U.S. Intelligence Community assessment, dated July 28, which was read to the Washington Post, said that "North Korea has produced nuclear weapons for ballistic missile delivery, to include delivery by ICBM-class missiles.”
Japan also said on Tuesday that it was possible that North Korea had already developed nuclear warheads.
"It is conceivable that North Korea's nuclear weapons program has already considerably advanced and it is possible that North Korea has already achieved the miniaturisation of nuclear weapons and has acquired nuclear warheads," Japan's Defense Ministry said.
"Since last year, when it forcibly implemented two nuclear tests and more than 20 ballistic missile launches, the security threats have entered a new stage," it added in a 563-page annual Defense White Paper.
It warned of an acute threat posed by North Korea's weapons programs as Pyongyang's continues a series of missile and nuclear tests in defiance of UN sanctions.
New estimations place the number of nuclear weapons in North Korea's arsenal at 60, as of last month's report by the U.S. Defense Intelligence Agency.
On Tuesday, U.S. President Donald Trump tweeted: "After many years of failure, countries are coming together to finally address the dangers posed by North Korea. We must be tough & decisive!"
North Korea's latest ICBM test showed Pyongyang may now be able to reach most of the continental United States, two U.S. officials have told Reuters.
The United Nations Security Council unanimously approved on Saturday new sanctions to punish the North including a ban on coal and other exports worth over $1 billion, a third of North Korea's $3 billion annual earnings.
North Korea said in response that it will launch "thousands-fold" revenge against the United States over the adoption of the tough sanctions.
Reuters and DPA contributed to this report