The Trump administration has cleared out the top echelons at the State Department. The latest departures include the assistant secretaries of state for Asia and Africa, who left this week.

Foreign governments are noticing all the vacancies — and so is Congress.

"We've had a lot of hearings and we've not had any Trump presentations at any of those hearings," said Maryland Sen. Ben Cardin, the ranking Democrat on the Senate Foreign Relations Committee. "There's no one to speak on behalf of the Trump administration."

Cardin spoke to reporters ahead of a Thursday hearing on Yemen, a country where the Trump administration has already carried out a military operation that resulted in civilian casualties and the loss of an American service member.

"I mean, Yemen could explode," Cardin said. "It is already boiling ... and yet we don't have a policy for Yemen. That's just one example."

The same vacuum could also be felt at the House Committee on Foreign Affairs, which held a hearing Thursday into Russian disinformation campaigns in Europe and the U.S.

Republican Chairman Ed Royce warned that Russia is trying to discredit Western democratic institutions and splinter NATO. But again, no Trump officials were present to speak on behalf of the administration.

Former Utah Gov. Jon Hunstman has reportedly accepted the job of ambassador to Russia — but there's been no official nomination yet. Congress might soon have an opportunity to ask him questions about Russia policy at a confirmation hearing. However, congressional aides say no such hearings are scheduled. The administration's few ambassadorial picks haven't even advanced to that stage.

Take Trump's apparent choice for ambassador to the U.K. At a luncheon back in January, Trump pointed to New York Jets owner Woody Johnson, describing him as "the ambassador Woody Johnson, going to Saint James," meaning ambassador to the Court of Saint James, the formal diplomatic title for the U.S. ambassador to Britain.

The White House has not yet made that official.

The Senate Foreign Relations Committee is still waiting for an ethics review and other paperwork to consider former Iowa Gov. Terry Branstad as ambassador to China. And it has yet to receive all the needed paperwork for two career diplomats to serve as ambassadors to the Democratic Republic of Congo and Senegal.

Meanwhile, the White House has yet to name any other top diplomats — some 60 slots remain vacant — or fill any of the 30 top jobs at headquarters requiring Senate confirmation, from deputy secretary of state on down to regional assistant secretaries. But according to ProPublica, the administration has placed hundreds of officials in agency jobs not requiring Senate confirmation — including nearly two dozen advisers and assistants at the State Department.

For now, career diplomats remain in the top jobs requiring Senate confirmation. But Cardin pointed out that Congress can't call these diplomats up to Capitol Hill to speak on behalf of Trump administration policies.

"It wouldn't be fair and that's not useful," Cardin said.

Four of his Democratic colleagues have writtento Secretary of State Rex Tillerson, raising concerns that the State Department is "experiencing significant management challenges, being cut out of important Administration foreign policy decisions, and facing potentially devastating budget cuts that would severely undermine U.S. diplomatic leadership and weaken National Security."

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