U.S. Defense Secretary Jim Mattis said that the U.S. military's competitive edge has eroded "in every domain of warfare" and blamed that partly on spending caps and congressional budget dysfunction.

Speaking on a military plane en route to Cairo, U.S. Defense Secretary Jim Mattis told reporters that as offensive operations against Islamic State in Syria entered their final stages, he expected the focus to move towards holding territory instead of arming Syrian Kurdish fighters.

U.S. Defense Secretary Jim Mattis says he cannot imagine the United States ever accepting a nuclear North Korea, warning that its rapidly advancing nuclear and missile programs would undermine, not strengthen, its security.

South Korea's defence ministry holds a welcome ceremony for U.S. Defense Secretary Jim Mattis.

U.S. Defense Secretary Jim Mattis on Wednesday praised Filipino soldiers for defeating pro-Islamic State militants in a five-month battle in Marawi City, the southern Philippines and said there were no credible allegations of human rights violations.

U.S. Defense Secretary James Mattis arrived in Iraq on Tuesday (August 22), just days after the start of an offensive to take back the city of Tal Afar from Islamic State.

U.S. Defense Secretary James Mattis said on Monday there would be a wider investigation into U.S. naval operations after an American warship collided with an oil tanker east of Singapore, leaving 10 sailors missing in the second accident involving a U.S. warship in two months.

U.S. Defense Secretary James Mattis says a conflict in North Korea would be the 'worst kind of fighting in most people's lifetimes.