Seou, Mar 14 (IANS): South Korea and the US have detected signs that North Korea is preparing to conduct another intercontinental ballistic missile (ICBM) system test as early as this week, informed sources here said on Monday.

Such indications emerged after Seoul and Washington accused Pyongyang on March 11 of having tested a new ICBM system on February 27 and March 5 ahead of a full-range ICBM test, reports Yonhap News Agency.

The North has characterised the two launches as "reconnaissance satellite" development tests. South Korean and US officials believe they involved the Hwasong-17 ICBM unveiled during a military parade in October 2020.

"Though we can't say definitively when a missile will be launched, we have been keeping close tabs on the possibility," a government source told Yonhap News Agency.

Asked to comment on the possibility of another North Korean missile test, an official at Seoul's Joint Chiefs of Staff refused to make "prejudgment" but stressed South Korea's "robust" readiness posture.

Weather conditions and other variables are expected to affect the timing of the North's possible launch.

Should the North press ahead with a new launch, the North could fire a missile from a transporter erector launcher (TEL) at the Sunan airfield, the site of the two previous tests, observers said.

In the earlier tests, the North fired the missile at a high angle from the airfield and engineered it to travel on a trajectory of a medium-range ballistic missile.

The missile fired on February 27 flew about 300 km at a top altitude of 620 km, while the one fired on March 5 travelled around 270 km at a top altitude of 560 km.