(CNN) North Korea is working on an advanced version of its existing KN-20 intercontinental ballistic missile that could potentially reach the United States, less than six months after it launched its first ICBM, a US official tells CNN. Additional new improvements are underway to North Korea's nuclear fuel, missile launchers, guidance and targeting systems as well, officials say. But all the officials CNN spoke with acknowledge that the US is already confronting a nuclear North Korea, because they have carried out a number of nuclear and missile tests. North Korea also appears to have made critical progress in developing warheads that will be capable of re-entering the Earth's atmosphere and reaching a target at intercontinental ranges. US officials are for now dismissing regional press reports that one tunnel completely collapsed, killing hundreds of North Korean workers.

Source: CNN November 02, 2017 00:33 UTC