WASHINGTON — The chairman of the special House committee created to investigate the 2012 terrorist attacks in Benghazi, Libya, pushed back Wednesday against critics who have called for him to abandon his efforts, saying “we should not move on” until more questions about the episode are answered.

At a hearing on Capitol Hill, the lawmaker, Representative Trey Gowdy, Republican of South Carolina, continued the Republicans’ criticism of how the Obama administration and former Secretary of State Hillary Rodham Clinton responded to the episode.

Mr. Gowdy asked why the administration did not initially use the word “terrorist” to describe those behind the attacks, in which four Americans were killed, and why the State Department’s requests for more security for its diplomatic compound were denied.

“I remain keenly aware that there are those on both sides of the aisle who have concluded that all questions have been answered, there is nothing left to do, no more witnesses to talk to, no more documents to review,” Mr. Gowdy said. “It is worth noting that some of those very same folks did not think that Benghazi should have been looked at in the first place.”