A Pentagon report to Congress says North Korea sees nuclear weapons as central to its security.
Weeks before his planned North Korea summit, President Trump is staring down a dealmaker's worst nightmare.
The United States on Monday issued a steep list of demands to be included in a nuclear treaty with Iran.
North Korea threatened to scrap a historic summit next month between Kim Jong Un, and U.S. President Donald Trump.
Secretary of State Mike Pompeo said the U.S. will need to "provide security assurances" to North Korea's Kim Jong Un.
North Korea's Foreign Ministry said all tunnels at the country's northeastern testing ground will be destroyed.
Staging a still-of-the-night arrival ceremony, President Donald Trump welcomed home three Americans freed by North Korea.
Thousands of U.S. troops in Syria and Iraq have been bolstered by the aircraft carrier Truman and its strike group.
Trump has a range of options as he makes his decision on whether to scrap the 2015 accord to curb Iran's nuclear program.
The U.S. Air Force has conducted dozens of developmental flight tests of the B61-12 guided nuclear gravity bomb.