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.
A U.S. Navy challenge to China's South China Sea claims last week may have allayed some of the concerns over broader American engagement. But Asian officials and diplomats are still hoping for a clearer articulation of Trump's policy when Mattis speaks in Singapore on Saturday.