Republican senators are eager to continue pushing through President Donald Trump’s executive branch nominees, but they are increasingly concerned about the slow pace of nominations being sent to the Capitol for the people who will be tasked with much of the nitty-gritty work of government. 

“I continue to ask for additional names to come forward, and I’m assured that they will be soon,” Republican Policy Committee Chairman John Barrasso said Tuesday.

The Wyoming Republican, who also serves as chairman of the Environment and Public Works Committee, said Republican senators have asked Vice President Mike Pence during the weekly policy luncheons about the lag in lower-level executive branch nominations — the deputy and assistant secretary types who require Senate confirmation.

“He assures us that there’s a long list coming soon,” Barrasso said.

Committee chairmen say they are ready to act, but there’s not always much to act on.

There were a total of just 18 civilian nominations formally sent to the Senate and awaiting committee action as of Tuesday, according to Senate records.

Even some Cabinet-level nominees are just getting in line. For instance, the nomination of Alexander Acosta to be Labor secretary, which Trump announced on Feb. 16, was only formally transmitted to the Senate on Tuesday morning, according to White House Press Secretary Sean Spicer.

Armed Services Chairman John McCain said he assumes Defense Secretary James Mattis is having difficulty filling out Pentagon leadership.

“I would think there’s some trouble,” the Arizona Republican said. “We’ve got one name and that’s the secretary of the Air Force. Of all the hundred appointees, we’ve got one and so there’s gridlock somewhere.”

Former New Mexico Rep. Heather Wilson has been making the rounds at the Capitol as the nominee to head the Air Force, but McCain said he was unaware of the source of the delay in getting nominees for other leadership positions within the Defense Department.

“They don’t communicate with me very often,” he said.

McCain’s panel did act quickly Tuesday to advance the re-nomination of national security adviser H.R. McMaster to maintain the rank of lieutenant general.

Vincent Viola, a businessman tapped to be Army secretary, withdrew from consideration after determining he would be unable to get his finances into compliance with federal ethics regulations.

Sen. Thomas R. Carper of Delaware, the ranking Democrat on the Environment and Public Works Committee, has a theory as to why the more routine practice of filling positions requiring confirmation has been moving so slowly: the ouster of New Jersey Gov. Chris Christie and his team from Trump’s transition operation shortly after the election.

“President Trump fired them,” Carper said. “So, they had done all this work on transition … and then they were gone. And they’ve had to bring in somebody new and start from scratch, and it shows.”

Democrats have slow-walked many of Trump’s nominees sent to the Senate, leading to a series of all-night sessions to get the president’s Cabinet and senior team in place. The same might happen with lower-level nominees.

Rod Rosenstein, the nominee to be deputy attorney general, faced members of the Judiciary Committee for a confirmation hearing Tuesday morning.

“I bet we’ve never had this many reporters for a hearing on the deputy attorney general,” said Sen. Amy Klobuchar, a Minnesota Democrat.

The interest came because of the recusal of Attorney General Jeff Sessions from decision-making about any Justice Department investigations related to Russian efforts to meddle with the 2016 presidential election, after the revelation of his own meetings with Sergey Kislyak, the Russian ambassador to the U.S.

Rosenstein declined to say Tuesday whether he would call for a special prosecutor to investigate potential links between Russia and the Trump campaign. He added that he was not in a position to make that call without having full access to information about potential inquiries.

Sen. Richard Blumenthal, a Connecticut Democrat, said before the hearing that he would seek to slow down Rosenstein’s confirmation without assurances about a special prosecutor.

Rosenstein and Rachel L. Brand, the nominee for associate attorney general, had a joint confirmation hearing Tuesday.

The next nominee up for a confirmation vote on the Senate floor is Seema Verma, Trump’s choice to lead the Centers for Medicare and Medicaid Services. Verma advanced through the Senate Finance Committee last week on a 13-12 party-line vote.

Majority Leader Mitch McConnell filed for cloture to limit debate on the Verma nomination Tuesday, setting the stage for her likely confirmation by week’s end.

The Intelligence Committee pushed back until their Thursday meeting a vote on the nomination of former Indiana Sen. Dan Coats to be the Director of National Intelligence. That is the same day that the Foreign Relations Committee is scheduled to mark up the nomination of David Friedman to be the administration’s ambassador to Israel.

A Foreign Relations Committee aide said the panel would be moving forward with review of other announced nominees within their jurisdiction.

“The administration has also announced nominees for various other positions, including ambassadorships to China, Senegal and Guinea-Bissau, and Congo; and U.S. governor to the [International Monetary Fund] and a number of international development banks,” the aide said.

In addition to Rosenstein and Brand and the nominees before the Foreign Relations Committee, the list of nominees includes Elaine C. Duke, who has a Wednesday hearing at the Homeland Security and Governmental Affairs Committee to be deputy secretary of Homeland Security.

John T. Bennett contributed to this report.