Trump 'disappointed' as further evidence of North Korean nuclear activity surfaces

US President Donald Trump has said he will be "disappointed" if it is confirmed that North Korea has begun rebuilding one of its missile launch sites.

Trump stated that it was too early to tell if intel regarding the Sohae launch facility at the Tongchang-ri site, which has previously been used for satellite launches, was accurate.

"It's a very early report. I would be very, very disappointed in Chairman Kim - and I don't think I will be - but we'll see what happens. We'll take a look. It'll ultimately get solved," said Trump.

Satellite images released on Wednesday appeared to show rebuilding works progressing on a launch site that North Korean leader Kim Jong Un had pledged to scrap, while a South Korean spy chief said on Thursday that he viewed activity at one of the Hermit Kingdom's intercontinental ballistic missiles plant as missile-related, according to reports from South Korea.

The Sanumdong factory was responsible for the production of the Hwasong-15 ICBM, which can fly more than 13,000 km (8,080 miles) and reach the US mainland.

Spy chief Suh Hoon reportedly also told politicians that North Korea had not shut down its uranium enrichment facility at the main Yongbyon nuclear complex after the first summit between Trump and Kim Jong Un, where Kim had committed to denuclearisation.

The sudden flurry of activity at North Korean nuclear sites comes after talks between Trump and Kim broke down last week when the North Korean leader demanded further sanction relief in exchange for progressing denuclearisation efforts.

While rebuilding works could by a gambit by the North Korean leader in order to pressure the US back to the negotiating table, hawkish White House national security adviser John Bolton has threatened the nation with fresh sanctions if it fails to scrap its nuclear weapons programme.