North Korea set to conduct tactical nuclear test anytime, U.S. and South Korean officials say

North Korean leader Kim Jong-un is preparing to soon carry out an atomic test as it continues to develop a tactical nuclear weapon, according to U.S. and South Korean officials, who laid out concerns about Pyongyang's unprecedented number of ballistic missile tests, as well as its first atomic test in five years. A nuclear test would signal that Kim has managed to grow his weapons program through the Trump and Biden administrations and despite the COVID-19 pandemic.

"We think they're ready to go. Kim just has to give the thumbs up," a senior U.S. State Department official told CBS News. 

A tactical nuclear device is designed to potentially be used on a battlefield.