South Korea's "Chosun Ilbo" newspaper reported Thursday that intelligence agencies had observed missile parts, believed to be the lower-half of an ICBM, being mobilized in the North, raising fears of an imminent missile test.

The South's Yonhap news agency then reported that two missiles, believed to be equipped with new engines, had also been loaded onto mobile launchers. 

Both reports quoted South Korean military officials.

"It was different from a conventional Musudan missile in its length and shape," a source told "Chosun Ilbo," referring to the intermediate-range missiles tested by the North last year. "It is possible they were moving it somewhere for assembly."

At a press conference Thursday, Roh Jae-cheon, a spokesman for South Korea's Office of the Joint Chiefs of Staff, declined to confirm the reports but said Seoul was monitoring North Korea's ICBM development.

Test launch imminent?

In his New Year's speech, North Korean leader Kim Jong Un said the country was close to testing an ICBM and would go on to conduct a series of nuclear and missile tests throughout the year. Experts on the country's missile program believe the claims to be creditable.

However, a test launch could be more imminent than initially estimated, with local media reporting it could potentially coincide with US President-elect Donald Trump's inauguration ceremony on Friday. Yonhap reported that Pyongyang had intentionally leaked the missiles' existence to send a "strategic message" to the incoming US President.

Pyongyang willfully showcased its ICBM development program to the world last year when it tested an ICBM engine made up of a cluster of smaller rockets.

The Washington-based think tank, 38 North, also reported Thursday that Pyongyang had restarted operation at its Yongbyon nuclear facility where it is believed to be able to reprocess polonium used in its nuclear warheads.

North Korea's missile program has seen the isolated country repeatedly sanctioned by the UN Security Council.

dm/rt (Reuters, AP)