US Defense Secretary James Mattis travels to Seoul and Tokyo today to reassure Washington's key East Asian allies after President Donald Trump unilaterally suspended military exercises in South Korea, sparking concern over his commitment to the region.
With the US president lauding North Korean leader Kim Jong Un as a "talented guy" as he seeks to persuade Pyongyang to give up its nuclear weapons, Mattis will head to South Korea Thursday afternoon after a two-day visit to China.
After discussions with top Korean officials, he will fly to Tokyo tonight for a day of meetings with Japanese counterparts.
Both countries have security alliances with the US guaranteed by treaty, but have been thrown off-balance by Trump's quick moves on negotiations with Kim.
Most striking of all, at a press conference after the two men's summit in Singapore earlier this month, Trump announced he would suspend joint military exercises with the South - with Seoul indicating that it was not informed beforehand.
US and South Korean forces have trained together for decades, and always characterised the drills as defensive in nature, while Pyongyang condemned them as rehearsals for invasion and often responded with provocations of its own.
Trump lamented the exercises' cost and adopted the North's description to call them "provocative", adding that at some point, "I want to bring our soldiers back home."
"In part that's what Mattis and his counterparts in Korea and Japan want to sort out - what are our operational bottom lines, and can we agree on certain things."