The ambassadorial post in South Korea has been vacant since US President Donald Trump took office in January last year.

The unusual long-haul vacancy has raised worries over a possible lack of policy coordination between the allies, which has gained urgency amid fast-changing security situations surrounding the Korean Peninsula.

Earlier this year, the US withdrew Victor Cha, a North Korea expert, from consideration for the job amid allegations over his policy differences with the Trump administration on the North and other issues.

South Korea and the US are currently planning to hold respective summits with North Korea. The leaders of the two Koreas are set to meet on the southern side of the truce village of Panmunjom on Friday.