"I think that there have been several conversations about that internally," Marc Short, White House director of legislative affairs, told reporters at a press briefing.

As nominees are put forward, "in many cases, it gets so delayed and so long that nominees have withdrawn from the process before actually being submitted to the Senate," he said. "That includes that post. But we've been having ongoing conversations about nominating someone soon."

US President Donald Trump has faced growing calls to appoint an ambassador to Seoul as tensions between the US and North Korea escalated over the regime's nuclear weapons and ballistic missile programs last year.

Last week Trump accepted an invitation from North Korean leader Kim Jong-un to meet to discuss the regime's denuclearization. Trump said he would hold the unprecedented summit by May.

Still, there has been no word on appointing an ambassador to Seoul, a role currently being served in an acting capacity by career diplomat Marc Knapper. (Yonhap)