Sources (but in particular North Korea’s Central News Agency (KCNA)) announced that a Hwasong-15 ICBM was test-fired at 3am Pyongyang time, November 29, 2017. It was launched near
Pyongsong, NK, and reached an altitude of 4,475 km over a flight distance of 950 km. It splashed down 53 minutes later at a planned point in the Sea of Japan. See MAP and Range Graph 1. below.
Wikipedia carries expert advice on the Hwasong-15 “Based on its trajectory and distance, the missile would have a range of more than 13,000 km (8,100 miles) – more than enough to reach Washington DC. and the rest of the US”. However preliminary calculations place the range from 13,000 km on the high-end "with light to no payloads" to 8,500 km with more standard 500 kg nuclear payloads. See Range Graph 2. below.
With a "light to no payload" the Hwasong-15’s range indeed covers all of Earth's continents, except South America and Antarctica. So the Hwasong-15 could hit the city of Darwin Australia with a 500 kg nuclear warhead and Australia’s more southerly cities with a light to no payload.
Experts may be again under-rating the pace of North Korea’s ICBM-nuclear warhead advances when they “cast doubt on North Korea’s ability to master the technology needed to design a warhead capable of withstanding the enormous pressure of re-entry into the earth’s atmosphere and suggested the isolated country may still be years away from developing a credible delivery vehicle for a nuclear weapon.”
Range Graph 2. Indicating Hwasong-15s of 13,000 km range with "light to no payloads" could hit Washington DC. and the rest of the US, (Courtesy many sources via US Public Radio International (PRI))