Mattis to focus on North Korea at Asian forum as allies seek clear U.S. policy

U.S. Secretary of Defense James Mattis walks past saluting cadets as he arrives for commencement ceremonies at the United States Military Academy in West Point, New York, U.S., May 27, 2017. REUTERS/Mike Segar

WASHINGTON (Reuters) - U.S. Defense Secretary Jim Mattis is expected to press for greater cooperation to contain North Korea's nuclear and missile threat at a regional security forum in Singapore later this week, where for years Washington has sought to spotlight China's expansion in the strategic South China Sea.

President Donald Trump has actively courted Chinese support on North Korea and abandoned an Asia-Pacific trade pact soon after taking office in January. That has raised concerns among Southeast Asian allies in the lead up to the annual Shangri-la dialogue starting on Friday that Washington might allow China a freer rein elsewhere in the region.