A Senate Democrat on Friday criticized Vice President Mike Pence's office for not sharing information about the vice president's recent trip to Ireland, during which he stayed at a golf resort owned by the president's company.

Sen. Gary Peters, D-Mich., the ranking member of the Senate's Homeland Security and Governmental Affairs Committee, reached out to Pence's office on Sept. 5 asking for specific information on the costs of the vice president's stay at Trump International Golf Club in Doonbeg, Ireland, including comparable rates for hotels nearby and across the country in Dublin, where Pence held meetings with Irish officials and business leaders.

In response, Pence's deputy chief of staff and counsel Matthew Morgan replied on Oct. 1 by enclosing a letter Pence's office sent on Sept. 19 to House Oversight Committee Chairman Elijah Cummings, who had also requested information about Pence's trip. That letter argued that commuting across the country to stay at Trump's Doonbeg resort made sense in light of last-minute changes to Pence's schedule and meetings the vice president held nearby. Morgan noted the State Department had approved of the lodgings, and said that the State Department, Department of Defense, and U.S. Secret Service may have the documentation sought by Cummings.

Peters responded Friday in a letter to Pence first obtained by ABC News, writing that the vice president's office's reply "failed to provide any information responsive to my request" -- specifically "any documents, travel vouchers, or cost information."

"This betrays either a contempt for or a lack of understanding of the serious concerns related to your decision to spend taxpayer dollars to patronize properties owned by President Trump," Peters wrote. He requested Pence share that information by Oct. 21.

In early September, the vice president held official meetings with Irish leaders in the nation's capital, Dublin, but flew back and forth across the country in Air Force Two to spend nights in the small village of Doonbeg, where his cousin runs a bar and his great-grandmother grew up. In Shannon, about an hour from Doonbeg, Pence met with Ireland's minister of foreign affairs and trade, as well as U.S. Customs and Border Protection staff.

A spokeswoman for Pence, Katie Waldman, told ABC News that Pence's office had voluntarily responded despite having "no obligation to do so."

"We have answered his question as to where the documentation may be found and it is up to the Senator and his staff to work with the Committee Chair to appropriately make requests for such information," Waldman said.