USAco, a domestic corporation, is the wholly-owned U.S. subsidiary of FORco, a foreign corporation, created in Country F. The U.S.-Country F tax treaty exempts interest payments from withholding taxes. USAcos financial statements for December 31 of the relevant tax year appear as follows:

BALANCE SHEET

Assets Liabilities & Owners Equity

Cash $300 Notes Payable $1200

Receivables $1500 Owners Equity $600

INCOME STATEMENT

Gross Income $1500

Administrative Expenses $1250

Interest Expense $300

The interest expense of $300 arises from a note payable from USAco to FORco. What is the maximum amount of interest USAco may deduct on its U.S. return? What can it do with any interest expense that is not deductible for that tax year?