U.S., South Korea to discuss North Korea threat in Seoul talks - Mattis

FILE PHOTO - Retired U.S. Marine Corps General James Mattis testifies before a Senate Armed Services Committee hearing on his nomination to serve as defense secretary in Washington, U.S. January 12, 2017. REUTERS/Jonathan Ernst/File Photo

SEOUL (Reuters) - U.S. Defence Secretary Jim Mattis said he would sound out ally South Korea on efforts to address North Korea's nuclear and missile programs as he arrived in Seoul on Thursday, including plans to deploy a U.S. missile defence system there.

Mattis' visit comes amid concern that the North may be readying to test a new ballistic missile, in what could be an early challenge for U.S. President Donald Trump's administration.