North Korea has embarked on a series of commercial ventures with a multibillion-dollar business network that stretches from Hong Kong to Angola as it battles to survive international sanctions, according to foreign officials and court documents.

Several of the projects, which involve industries ranging from taxis to oil exploration, have the same stylised logo: the letters KKG. It is not clear whether KKG is merely a brand or a large North Korean state-owned enterprise, as claimed by the Chinese supplier of its taxi fleet.

But US and Asian officials say it is an important part of Pyongyang’s web of business interests, backed by a shadowy arm of Kim Jong Un’s totalitarian regime called Office 39. The US and EU have singled out Office 39 and its front companies, which lead the regime’s efforts to generate much-needed foreign currency, for sanctions designed to curb North Korea’s nuclear weapons programme and squeeze the government’s finances.