James Mattis has said a diplomatic solution to the situation with North Korea cannot be ruled out.
Tension has been growing between the United States and the regime in Pyongyang as the latter continues to conduct missile tests.
The most recent was a test deemed to be a "prelude" to a strike on Guam, with the fired missile moving over the island of Hokkaido in Japan and causing panic as residents were urged to seek shelter. The recent missile test was met by international condemnation from political leaders.
Mattis, speaking to the press as he met his South Korean counterpart Song Young-moo at the Pentagon, said America is "never" out of diplomatic solutions with North Korea.
This is an open contradiction of Donald Trump, who posted this on Twitter in response to the test: