The announcement of the defence alliance, and Australia's related decision to tear up a deal to buy French submarines in favour of American nuclear-powered vessels
A report from US intelligence experts released in April said North Korea could resume nuclear tests this year as a way to force Biden's administration to return to the negotiating table.
Sung Kim, appointed by Biden last month, is a Korean-American diplomat who had the same role under former President Barack Obama, and helped set up Trump's summits with Kim.
On China, which has been accused of repressing its minority Uyghur population and cracking down on rights in Hong Kong, and Russia, Raab said the "door was open" to better ties.
But civilian groups in the South, mainly led by defectors, continued their activities, raising fears of retaliation among locals living along the frontier.