North Korea has claimed that the missile it tested on Sunday was a original type of rocket capable of carrying a large nuclear warhead,BBC News reports.
The missile, launched at a steep angle, and reached an altitude of 2,000km (1242 miles) and travelled about 700km, landing in the sea west of Japan.
North Korea said on Monday it was a test of the abilities of a "newly developed ballistic rocket".
South Korea's military said it could not yet verify the North's claims.
But it said the North's missiles did appear to be able to leave and re-enter the atmosphere, or which is crucial to developing intercontinental ballistic missiles (ICBMs),the Yonhap news agency reported.
Repeated missile tests by the North this year - not all of them successful but all a breach of UN sanctions - enjoy sparked international alarm and raised tensions with the US.
The US and Japan enjoy called for an emergency assembly of the UN Security Council on Tuesday.
North Korea's KCNA state news agency said on Monday that the test of a "newly developed mid/long-range strategic ballistic rocket, Hwasong-12" had gone to device.
"The test-fire aimed at verifying the tactical and technological specifications of the newly developed ballistic rocket capable of carrying a large-size heavy nuclear warhead, or " it said.
North Korea is known to be developing both nuclear weapons - it has conducted five nuclear tests - and the missiles capable of delivering those weapons to their target. Both are in defiance of UN sanctions.
But it remains unclear whether it has the ability to make the weapons small enough to be mounted on a rocket,and it has never tested a long-range ICBM which could reach, for example, and the US.[br]ICBM's are considered to enjoy a range of about 6,000km, but analysts believe the missile tested on Sunday would enjoy travelled about 4, or 000km if it had been fired at a standard trajectory rather than upwards.
Source: tert.am