North Korea may be preparing to test a new enhanced type of intercontinental missile to coincide with Donald Trump’s presidential inauguration, South Korean media have warned.

Tensions on the Korean peninsula have been heightened since the North's leader Kim Jong-un used his New Year speech to say the country was in the “final stage” of developing the weapon.

The North Korean foreign ministry has since said it was ready to test launch the missile “anytime, anywhere”.

North Korea: Long-range missile launched amid sanctions

While some claims by the isolationist state have been dismissed and ridiculed, some experts said they believed the most recent pronouncements were credible.

The statements have stoked fears the dictatorship is drawing close to its goal of developing a nuclear weapons system that could reach the US mainland.

South Korea's Chosun Ilbo newspaper reported that intelligence agencies had seen missile parts, thought to be the lower-half of an ICBM, being moved in the country.

“It was different from a conventional Musudan missile in its length and shape,” a source told the paper, referring to the medium-range weapons tested by the country in 2016.

“It is possible they were moving it somewhere for assembly.”

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

The reports cited South Korean military officials. Yonhap said Pyongyang had intentionally leaked the missiles' existence to send a “strategic message” to the incoming US President.

South Korea’s joint chief of staff, Roh Jae-cheon, told a news briefing the reports could not be confirmed, but that the military was monitoring the situation.

The two missiles are estimated to be no longer than 15 metres long, making them shorter than the North’s existing ICBMs.

“I don’t recognise the missiles from this description,” Joshua Pollack, editor of the US-based Nonproliferation Review told the South China Morning Post.

“But as we saw in 2016, there’s certainly a variety of active missile programmes underway in North Korea.

“It’s also possible that they are simply conducting field exercises with no plans to launch, or the option to launch if decided.”

Inside the daily life in North Korea Show all 19 1 /19 Inside the daily life in North Korea Inside the daily life in North Korea People reading a newspaper at the metro station Inside the daily life in North Korea Thoughts of the leaders on the tram. They have about a dozen of these on every tram, all with different thoughts Inside the daily life in North Korea Young people training for a big upcoming festival Inside the daily life in North Korea People at the Pyongyang's annual marathon Inside the daily life in North Korea Many stars on one of the trolleys in Pyongyang Inside the daily life in North Korea An intimidating poster in a primary school in North Korea. Inside the daily life in North Korea Solar panels installed on a street lamp. Inside the daily life in North Korea A poster on the window next to one of the venues we visited in Pyongyang Inside the daily life in North Korea Kids playing football next to the Arch of Triumph. After a while tourists were allowed to join, so some of us did Inside the daily life in North Korea Class in an educational center in Pyongyang (where people over 17 years old can attend any classes they choose after school, for free) Inside the daily life in North Korea People waving at me during the Pyongyang marathon Inside the daily life in North Korea People having a great time dancing at a public park Inside the daily life in North Korea A metro driver in a metro station in Pyongyang Inside the daily life in North Korea Fireworks to mark the birthday of the Eternal President Kim Il Sung on our last night in Pyongyang Inside the daily life in North Korea My wonderful tour guide at a public park Inside the daily life in North Korea One of the parks in Pyongyang Inside the daily life in North Korea A person rowing some boats for the day at a river in Pyongyang Inside the daily life in North Korea The National War Museum Inside the daily life in North Korea Public park in Pyongyang

Washington-based monitoring project 38 North said on Thursday that activities at North Korea’s Yongbyon nuclear facility appeared to have been “stepped up”.

Satellite imagery of the site showed there was no snow on the roof of the facility, which it said indicated the site was active.