The president says he has never spoken directly to the North Korean leader, but that he and South Korean President Park Geun-hye remain open to talks.

Southern California is home to one of the largest Korean populations in the United States. Some in this community have been especially alarmed by North Korea's latest threats of a nuclear attack, but many think the North's provocations are a lot of bluster.

Adm. Samuel Locklear says the U.S. could intercept a ballistic missile launched at the U.S. homeland or Pacific allies.

U.S. officials wonder whether North Korea's successful rocket launch this week helped Iran 鈥� another country whose nuclear program concerns the U.S. The two countries have worked together in missile design, but it's unclear who's helping whom.