US officials say evidence suggests new long-range ballistic missiles are being built. (Image: PA/KCNA).
American spy agencies suspect that North Korea is building new missiles in the same research facility that manufactured the country's first ballistic missiles capable of reaching the US, reports said.
According to The Washington Post, security officials said new evidence, including satellite photos taken in recent weeks, suggests that work is under way on at least one, possibly two intercontinental ballistic missiles at a facility on the outskirts of Pyongyang.
The report casts further doubt on US president Donald Trump's claims of victory last month in disarming North Korea.
Last week, a US research group said North Korea had started dismantling key facilities at its main satellite launch site.
After the US President met with North Korean leader Kim Jong Un in Singapore, Mr Trump declared on Twitter: "There is no longer a Nuclear Threat from North Korea."
It comes as rare talks between North and South Korea ended with no agreement, despite top delegates saying they had a meaningful discussion on easing their countries' decades-long military stand-off.