North Korea's Kim Jong-Un Threatens To Use Nuclear Weapons

Kim Jong Un has issued a warning about the potential use of nuclear weapons in conflicts involving South Korea and the US. In a speech to North Korean veterans, he accused the US of demonizing North Korea and described the South Korean government as being led by confrontational maniacs and gangsters.

What was the context of Kim Jong Un's speech?

How did Kim Jong Un describe the South Korean government?