Treasury Secretary Steven Mnuchin has flown on military aircraft seven times since March at a cost of more than $800,000, including a $15,000 round-trip flight to New York to meet with President Trump at Trump Tower, according to the Treasury Department’s Office of Inspector General.

The inquiry into Mr. Mnuchin’s air travel, prompted by an Instagram posting by his wife, found he broke no laws in his use of military aircraft but lamented the loose justification provided for such costly flights.

“What is of concern is a disconnect between the standard of proof called for” by the Office of Management and Budget “and the actual amount of proof provided by Treasury and accepted by the White House in justifying these trip requests,” the inspector general wrote.