South Korean officials say they see signs North Korea is preparing for another intercontinental ballistic missile launch, which could reach the United States and Guam. They also restated what U.S. intelligence said for the first time recently: they believe North Korea has miniaturized a nuclear device that can be fitted to a ballistic missile.

FOX's Lucas Tomlinson has the latest from the Pentagon:

U.S. officials tell FOX the Japan-based aircraft carrier USS Ronald Reagan will go to sea in the next few days for previously scheduled training. Not as a result of North Korea's latest nuclear test over the weekend...

Just hours after Defense Secretary Mattis warned he had many military options, South Korea began a live fire exercise involving F-15 fighter jets and land based ballistic missiles into the Sea of Japan.

A South Korean warships fired off a missile at sea, the latest warning shot aimed at Pyongyang. The mock target: the distance to North Korea's nuclear test site.

At the Pentagon, Lucas Tomlinson, FOX News.

Follow Lucas Tomlinson on Twitter: @LucasFOXNews