China blames U.S. for N.Korea missile crisis

USA military has detected "unprecedented" levels of submarine activities in North Korea suggesting increased development of sea-based nuclear attack capabilities.

Citing US officials, The Washington Post last week said the Pentagon's Defense Intelligence Agency (DIA) now believes North Korea will be able to deploy an ICBM as soon as next year.

Still, Elleman said Pyongyang is learning fast and that depending on North Korea's testing schedule, a deployment next year is possible.

"It would be a war that fundamentally we don't want", Mattis said, but "we would win at great cost". US Permanent Representative Nikki Haley responded by saying "the time for talk (with North Korea) is over". "And he has told me that to my face", Graham said.

Separately, CNN, quoting a U.S. defence official, reported that North Korea had been showing "highly unusual and unprecedented levels" of submarine activity, in addition to its third "ejection test" this month.

The ejection test was carried out on land at the Sinpo Naval Shipyard on Sunday, where a submarine base is located, a USA defense official told CNN. They gave no other details about the increased submarine activity.

Cold ejection involves the use of pressurized gas to expel a missile from the launch tube before ignition to reduce the risk of catastrophic damage to the vessel.

The shipyard is in Sinpo, a port city on the east coast where the North had previously conducted tests of submarine-launched ballistic missiles.

Abe, speaking after a phone call with U.S. President Donald Trump, told reporters on Monday that they agreed more action was needed to mitigate the threat from North Korea.

The Pentagon acknowledged military-to-military talks with US allies Japan and South Korea after the test.

North Korea has successfully tested two land-based intercontinental ballistic missiles this year, with the latest test last week indicating the missile could reach Los Angeles, Denver, or Chicago.

USA and South Korean experts on Tuesday said Japanese video footage capturing the Hwasong-14's re-entry vehicle shortly before it crashed into the sea suggests it failed to survive the extreme heat and pressure after re-entering the Earth's atmosphere following its launch from northern North Korea on Friday.

Michael Elleman, of the International Institute for Strategic Studies and the 38 North Analyst think tank, said it appears that the "re-entry vehicle" that would carry a warhead back into Earth's atmosphere from space had failed during the second test.