The South Korean government "will never sit idle," Seoul's ambassador to London has said, as the U.S. ally worries that North Korean troops deployed alongside Russian forces against Ukraine could accrue valuable combat experience far from the Korean Peninsula.

Ukrainian and South Korean intelligence services have said that many of the troops deployed to Russia are some of Pyongyang’s best, drawn from the 11th Corps, also known as the Storm Corps - a unit trained in infiltration, infrastructure sabotage and assassinations.

Fox News chief national security correspondent Jennifer Griffin provides details on President Biden's decision to authorize Ukraine to use U.S. missiles against Russia.