The State Department is riddled with key vacancies as Trump seeks nuclear talks with North Korea

As President Donald Trump steps up efforts to engage North Korea in nuclear disarmament talks, the State Department is in the most turmoil since the president's inauguration.

The latest upheaval came Tuesday with the sudden firing of Secretary of State Rex Tillerson, who was dismissed with few details provided by the White House. Trump picked CIA Director Mike Pompeo to be the next secretary of State.

The moves followed Trump's abrupt announcement last week of a yet-to-be-arranged meeting with North Korean leader Kim Jong Un.

But the prospects for any diplomatic breakthrough are clouded by senior State Department vacancies, including a permanent U.S. ambassador to South Korea. The Trump administration has also yet to fill other positions critical to any talks with North Korea, including a permanent undersecretary for arms control and international security affairs, as well as a permanent assistant secretary for East Asian and Pacific Affairs.

Dozens of other key diplomatic jobs remain unfilled, including ambassadors to key U.S. allies such as Germany, Australia and Saudi Arabia.

More than two dozen ambassador posts are waiting for nominations to be put forward; nominees for more than a dozen others are waiting for confirmation.

The vacancies have strained ties with key U.S. allies. On Tuesday, Germany's Deputy Foreign Minister Michael Roth tweeted that Tillerson's firing won't help.

"The dismissal of Rex #Tillerson does not make anything better," Roth said in a tweet.

Roth tweet

Tillerson's departure also adds to ongoing uncertainty about Trump's promised reorganization of the State Department. Last fall, the senior official charged with overseeing that effort stepped down after less than four months on the job amid widespread criticism from current and former American diplomats.

Rumors about friction between Trump and Tillerson began circulating last year. In October, NBC News reported that Tillerson called the president a "moron," something Tillerson never directly denied. Tillerson continued to insist his relationship with the president was solid and brushed off rumors of strain between them.

His departure is just the latest in a high-velocity revolving door that has dogged the Trump administration. Last week chief White House economic advisor Gary Cohn resigned after a heated dispute over Trump's announcement of steep steel and aluminum tariffs, a move Cohn opposed.