WASHINGTON (AP) -- The US special envoy for North Korea, Stephen Biegun, is expected to be nominated as early as this week to be second-in-command at the State Department, officials said Monday.

Two Trump administration officials and a congressional aide familiar with the selection process said the White House is expected to nominate Biegun to be the next deputy secretary of state in the coming days. The officials were not authorized to discuss the matter publicly and spoke on condition of anonymity.

Biegun would replace John Sullivan, who has been nominated to be the next US ambassador to Russia. Both positions require Senate confirmation.

Biegun has had a prominent role in the delicate negotiations that led to historic meetings between President Donald Trump and North Korean leader Kim Jong-un.

A former Ford Motor Co. executive who served in previous Republican administrations and has advised GOP lawmakers, Biegun has led as yet unsuccessful negotiations to get North Korea to give up its nuclear weapons since being appointed to his current post in August 2018. He is expected to keep the North Korea portfolio if he is confirmed to the new post, the officials said.

His nomination has been expected since mid-September, but its timing has been unclear amid turmoil in the State Department over the House impeachment inquiry into the administration's policy toward Ukraine.

Sullivan was nominated to be envoy to Moscow in September although his confirmation hearing before the Senate Foreign Relations Committee was just set for Wednesday, making Biegun's nomination to fill the soon-to-be vacant No. 2 spot at the State Department more urgent.

Sullivan's confirmation hearing is likely to be dominated by questions from committee Democrats about Russian meddling in the 2016 presidential election and his role in Ukraine policy.

Former US Ambassador to Ukraine Marie Yovanovitch testified to impeachment investigators earlier the month that Sullivan was the official who informed her that she had lost Trump's confidence and was being recalled early from Kyiv. Democrats are expected to use Wednesday's confirmation hearing to press Sullivan on the extent of his involvement in Ukraine and why the department bowed to a campaign to oust Yovanovitch spearheaded by Trump's personal lawyer Rudy Giuliani. (AP)