North Korean leader Kim Jong Un is threatening the United States again.
This time he says they are prepared to strike with small, lighter nuclear weapons.
Defense Secretary Chuck Hagel says the weeks of threats are starting to become a major concern, especially for US allies like Japan and South Korea.
The military is also sending a missile defense system to a base in Guam.
Experts say a North Korean nuclear missile cannot reach the US, but can reach the 28,000 US troops in South Korea.
But it's not just the troops and people living in Korea that are concerned. A local man originally from South Korea says North Korea should rethink their stance, because he's seen the affects of war.
"I've been through two wars. I have seen tragedy, many people killed, wounded, starvation. There should not be war, at all cost. We should avoid war at all costs," said Kenneth Kim.
Kim has spoken with his family currently in South Korea. He says they are very scared, and are considering moving further south in hopes of avoiding any conflict.