Typhoon Mawar is now headed towards Philippines and is likely to weaken east of Taiwan
The move comes six months after the US Defense Secretary Mark Esper and Singapore Defense Minister Ng Eng Hen signed a memorandum of understanding for Singapore to set up a fighter jet training detachment in Guam.
The scheme to target the island, a key US military stronghold, was intended to "signal a crucial warning" as "only absolute force" would have an effect on the US leader, the North said.
The threat came hours after US President Donald Trump threatened Pyongyang with "fire and fury" over its missile program and days after the UN Security Council levied new sanctions on North Korea over its growing nuclear arsenal.
The United States said it would soon send a missile defence system to Guam to defend it from North Korea, as the US military adjusts to what defence secretary Chuck Hagel called a "real and clear danger" from Pyongyang.