Washington: After nearly a year and a half in office, the Trump administration has succeeded in filling one of the most important US diplomatic posts, with the Senate unanimously approving former Pacific commander Harry Harris as the next US ambassador to South Korea.

The Senate confirmed Harris's nomination in a voice vote late on Thursday, and he is expected to take up his post in Seoul, which has been vacant since president Donald Trump's January 2017 inauguration, in early July.

The retired admiral will take office at a time when South Korea and the United States are working closely together to engage with North Korea to try to persuade it to abandon a nuclear weapons program that now threatens the United States.

That engagement led to an unprecedented summit between Trump and North Korean leader Kim Jong-un on June 12, but protracted follow-on negotiations are expected to be needed before any concrete deal is reached with Pyongyang.

Harris, who was born in Japan to a Japanese mother and American father, previously served as head of the US Pacific Command in Hawaii, which includes the 28,500-strong US force in South Korea, a key US ally.