The Hwasong-14 is likely a
two-stage version of the
Hwasong-12 first tested in May 2017. The second stage appears to have increased its range. The first stage engine appears very similar to the Hwasong-12. With a single
liquid fuel engine, it has four
vernier thrusters for stability and guidance. Based on images, the missile is estimated to be long and wide, and has a takeoff mass of . A detailed analysis by the
Bulletin of the Atomic Scientists claims that the current variant of the Hwasong-14 may not even be capable of delivering a first-generation nuclear warhead to
Anchorage, Alaska. But even if North Korea is now capable of fabricating a relatively light-weight, "miniaturized" atomic bomb that can survive the extreme reentry environments of long-range rocket delivery, it will, with certainty, not be able to deliver such an atomic bomb to the lower 48 states of the United States with the rocket tested on 3 July and 28 July. A first-generation North Korean nuclear missile warhead is estimated to weigh . enough to reach Anchorage and
Honolulu, Hawaii, to as much as , but with a lighter warhead at . The -range is based on the
reentry vehicle carried during the July 2017 tests, although such a payload is much lighter than North Korea is believed to be capable of weaponizing. Although the missile is mounted on a transporter erector launcher, it is launched from a detachable platform on a concrete pad. This could have several operational ramifications. It may increase the time required to launch the Hwasong-12, and limit the number of launch locations to pre-sited and pre-constructed launch pads. and has been modified to operate as the boosting force for the
Hwasong-12 and -14, which is capable of producing a thrust of . North Korea acquired an unknown number of RD-250 engines. Its need for an alternative to the failing
Hwasong-10 and the recent appearance of the RD-250 engine along with other evidences, suggests the transfers occurred in 2015–2017. South Korean intelligence data shows North Korea received 20 to 40
RD-251 engines from Russia in 2016. Ukraine rejected this theory, claiming it was "most likely provoked by Russian secret services" to "cover their own crimes", and to prevent United States from transferring
FGM-148 Javelin anti-tank missile to Ukraine. Engine maker
Yuzhnoye Design Office denied that the engines were supplied to North Korea by Ukraine. In August 2017, the
State Space Agency of Ukraine claimed that the rocket engine used during 28 July 2017 North Korea's missile test was RD-250 made at a Ukrainian factory, but solely for use in
Tsyklon space rockets supplied to Russia. The space agency chief said that according to Ukrainian information, "Russia today has between 7 and 20 of the Tsyklon rockets...They have these engines, they have the documentation. They can supply these engines from the finished rockets to whoever they want." The agency also claimed that a total of 223
Tsyklon-2 and
Tsyklon-3 rockets were supplied to Russia. Furthermore, he stated that North Korea cannot produce the fuel for the RD-250 (
N2O4 and
UDMH), and that it must have been produced either in China or in Ukraine. According to German expert Norbert Brügge, the second stage engine has a thrust of . ==History==