From Wikipedia:
First test flight
The first publicly announced flight test was on 4 July 2017, to coincide with the US Independence Day celebrations. This flight had a claimed range of 933 kilometres (580 mi) eastwards into the Sea of Japan (East Sea of Korea) and reached an altitude of 2,802 kilometres (9,193,000 ft) during a 39-minute flight.[29]
This range was deliberately shortened, to avoid encroaching on other nations' territory, by 'lofting' the missile: firing it on a trajectory that was inefficiently high, rather than optimised for range. This allows the missile's performance to be tested and demonstrated, without requiring a huge test range.[29]
A prediction for the possible range, following an optimum trajectory, has been given at 6,700 kilometres (4,200 mi)[30] or as much as 10,400 kilometres (6,500 mi) not taking into account the Earth’s rotation. If true, then this brings the U.S. states of Alaska and Hawaii within the missile's range.[29]
Second test flight
Preparations for a second test flight were detected by US intelligence as early as 20 July.[28] On 28 July, the missile was fired at 11:41 p.m local time, the first time which a night time launch was carried out.[31][32] The missile was fired at a lofted trajectory with apogee of 3,700 km (2,300 mi), landing 998 km (620 mi) away with a total flight time of approximately 47 minutes. Based on the data from the test flight, if the missile were fired at the optimal efficient trajectory, it is predicted that the maximum effective range would exceed 10,000 km (6,200 mi). If factoring in the rotation of the Earth, which may provide a range boost when travelling eastward, the Hwasong-14’s coverage area would include the US West Coast, Chicago, and possibly even New York,[16] but only with a substantially reduced payload.[33]
In other words, the missiles were deliberately launched in an unusually high trajectory in order to reduce the effective range, in order to not encroach on neighboring territories, and to keep the missile within DPRK's telemetry range. Do you understand the part where it says it could reach Alaska, Hawaii, and the continental US West Coast? And New York with a reduced payload? Does this count as an ICBM in your dictionary?
The "claims" were made by DPRK's own KCNA news agency, and confirmed by US, Japanese and ROK trackers.