Updated

The American defense secretary has arrived in South Korea to consult with his counterpart and U.S. military commanders on countering North Korea's nuclear weapons program.

Jim Mattis is emphasizing the Trump administration's push for a diplomatic solution to the problem. But he also has warned that the U.S. is prepared to take military action if North Korea does not change course.

He will be meeting on Saturday with South Korean officials as part of an annual consultation on defense issues on the Korean peninsula.

Mattis is being joined in Seoul by the chairman of the U.S. Joint Chiefs of Staff, Gen. Joseph Dunford.

President Donald Trump is scheduled to visit Seoul in November.