Melania Trump’s hotel bills for a one-day trip to Toronto last year totalled $174,000 (£135,000), according to official US Government accounts.
What the taxpayer funds were spent on is not clear but transportation costs and those of her advance team are detailed separately, Quartz reports.
She did not stay the night at the “downtown Sheraton”.
Six separate charges ranging from just under $12,000 (£9,330) to nearly $49,000 (£38,000) are labelled “HOTEL ROOMS” payed to “Miscellaneous Foreign Awardees″.
Trump’s spokeswoman, Stephanie Grisham, implied in an email to Quartz that the first lady’s “advance team” was responsible for some of the costs, but as detailed above, these were filed separately.
The first lady was in Toronto in September 2017 to help kick off the Invictus Games.
Her itinerary shows hotel stops including a 20-minute meeting with Prince Harry at the Sheraton, and a reception later with 100 competing US athletes, also at the Sheraton, where she gave a short speech.
Trump’s trip began just after noon and she returned just after midnight to Andrews Air Force Base.
The amounts dwarf the $95,000 (£74,000) cost of Trump’s stop at the InterContinental Cairo Semiramis last month, at the end of her tour of Africa last month.
At the time Grisham complained about the reporting of the story but shot herself in the foot when she inadvertently highlighted the stop was for less than six hours, not the overnight trip that media was reporting.
It’s estimated that each of Donald Trump’s weekend trips to his Mar-a-Lago resort in Florida costs $1million (£780,000).
He has so far spent 72 days at the property since taking office.