-- Donald Trump tweeted Monday night that North Korea will not be able to develop a nuclear weapon that is capable of reaching the United States, saying "It won't happen!"
North Korea's leader, Kim Jong Un, said Sunday that the country is in the "final stages" of preparing an intercontinental ballistic missile, which can deliver a nuclear weapon, according to the Associated Press.
But the AP said it was not clear if that meant that the country, which has claimed that it conducted several nuclear tests in recent years, was ready to test an ICBM.
North Korea has conducted several medium- and long-range missile tests in recent years.
Trump has been vocal about his planned nuclear weapons policy, saying that the U.S. needs to "greatly strengthen and expand" its nuclear capabilities.
It wasn't immediately clear if Trump was referring to increasing the number of weapons or modernizing existing systems.