3 U.S.C. § 103 : US Code - Section 103: Traveling expenses

Search 3 U.S.C. § 103 : US Code - Section 103: Traveling expenses

There may be expended for or on account of the traveling expenses
of the President of the United States such sum as Congress may from
time to time appropriate, not exceeding $100,000 per annum, such
sum when appropriated to be expended in the discretion of the
President and accounted for on his certificate solely.