WASHINGTON -- A Republican senator has delayed President Barack Obama's nomination of Tammy Duckworth, an injured Iraq war helicopter pilot, to be an assistant secretary at the Department of Veterans Affairs. 

The Senate Veterans Affairs Committee didn't vote on the nomination Thursday because North Carolina Sen. Richard Burr asked that the panel hold off. Burr, the top Republican on the committee, wants Duckworth and the White House to answer some of his questions. Burr's spokesman, David Ward, would not say on Friday what the questions concerned. 

"He's doing his due diligence ... to ensure that veterans have the best representation possible," Ward said. 

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

Duckworth, a major in the Illinois National Guard, lost both her legs and partial use of one arm in a rocket-propelled grenade attack in 2004. She ran for Congress in 2006, but lost. She's currently the director of the Illinois Department of Veterans Affairs. 

On Feb. 3, Obama nominated her to the position of assistant secretary of public and intergovernmental affairs. Her duties would include directing VA's public affairs operations, as well as programs for homeless veterans. 

On Thursday, the committee did approve the nomination of W. Scott Gould to be deputy VA secretary.