(CNN) Interior Secretary Ryan Zinke is coming under criticism after he responded with a "flippant" comment to a congresswoman's story about her grandfathers' detention in internment camps for Japanese-Americans during World War II.

Rep. Colleen Hanabusa discussed two of her grandfathers' detention to the Interior Secretary during a hearing on Thursday. She said her grandfathers did not speak about their experiences until late in their life. The Hawaii Democrat sought Zinke's assurance that $2 million in grant money to maintain the infamous historic sites would be preserved in his budget.

"I believe that it is essential that we as a nation recognize our darkest moments so that we don't have them repeat again," she said.

"Konnichiwa," Zinke said in response to Hanabusa's testimony, using the Japanese word for "good day" or "good afternoon."

A person sitting in the hearing appeared to gasp at the remark.