Trump has complained bitterly about stonewalling by Democrats, who have withheld support for many of the president's Cabinet-level nominees. Half of Trump's picks were approved by slim majorities. Education Secretary Betsy Devos required a tie-breaking vote from Vice President Mike Pence.

Democrats successfully torpedoed one of Trump's Cabinet choices before a vote, pressuring fast food executive Andrew Puzder to withdraw as a nominee for secretary of Labor.

And they have offered support for only three of the top 15 Cabinet positions, joining Republicans to approve Defense Secretary James Mattis, Veterans Affairs Secretary David Shulkin and John Kelly to head the Department of Homeland Security. Most Senate Democrats have opposed the remaining nominations.

But Democrats in Congress can't stall nominations that haven't been made.

As of Thursday, the White House had yet to put forward the names of candidates for 475 of the 554 key positions that require Senate confirmation, according to the Partnership for Public Service, a nonpartisan group that advises incoming administrations.

That doesn't include the thousands of political appointments that don't require congressional approval.

Transitioning in just a few months to a new administration charged with overseeing 2.2 million federal employees is never easy. With no prior government experience, and few Washington insiders on the transition team, the Trump administration is hitting a steep learning curve, according to Max Stier, founding president and CEO of the Partnership for Public Service.

"No prior administration has done well at this," he said. "But Trump is even further behind."

The process has reportedly been slowed by Trump's close involvement in choosing nominees, and by turf wars between his inner circle and his Cabinet members.

The longest list of empty desks waiting for nominations is at the State Department, where more than 100 jobs are vacant, including the dozens of ambassadors appointed by the Obama administration who were fired by Trump on Inauguration Day.

In the meantime, Trump has quietly hired some 400 staffers — without Senate approval — to begin working throughout the executive branch and coordinating with the West Wing.

The White House did not immediately respond to a request for comment.

Here are the departments and agencies with the remaining unfilled jobs and the status of the nomination process, according to the Partnership for Public Service. Hover over a symbol for details.