GOP Sen. Joni Ernst of Iowa. (Photo: Nicki Kohl/Telegraph Herald via AP)

Sen. Joni Ernst, R-Iowa, said Tuesday that she has “concerns” about the frequency of President Trump’s trips to his Mar-a-Lago residence and particularly about his use of the Palm Beach, Fla., venue to host foreign leaders.

Ernst was holding a town hall in Wall Lake, Iowa, when a constituent inquired about the cost of Trump’s trips to the “Winter White House,” as Trump has called it. The president has spent seven of his 13 weekends as president at the estate. According to the Associated Press, cost estimates for each trip have ranged from $1 million to three times that.

“I agree with you,” Ernst responded. “I do wish that he would spend more time in Washington, D.C. That’s what we have the White House for.”

The senator also alluded to similar concerns among other congressional Republicans, and said they may try raising the issue with Trump.

“I have not spoken to him about the Florida issue yet,” Ernst said. “But that is something I think that has been bothering not just me, but some other members of our caucus. So I think that is going to be a topic of discussion that we have when we get back to Washington, D.C.”

Ernst specifically questioned Trump’s use of Mar-a-Lago to host foreign heads of state, including Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping. Trump was having dinner with Xi when he ordered a missile strike on a Syrian air force base earlier this month. (Trump later recalled that he was eating the “most beautiful piece of chocolate cake that you’ve ever seen” when he informed Xi of his action.)

“We would love to see more of those State Department visits in Washington, D.C.,” Ernst said. “I think it’s smart that he does business in Washington, D.C.”