U.S. Defense Secretary Jim Mattis issued a stark warning to North Korea on Wednesday, telling Pyongyang that it should stop any actions that would lead to the "end of its regime and the destruction of its people."

Mattis' words, some of the strongest he has issued on North Korea, followed incendiary comments from President Donald Trump, who said on Tuesday that threats to the United States from Pyongyang would be met with "fire and fury."

Trump's unexpected remarks prompted North Korea to respond by saying it was considering plans for a missile strike on the U.S. Pacific territory of Guam.