Pursuant to 22 U.S.C. 3102, portfolio investment means any international investment which is not direct investment. “International investment” means (a) the ownership or control, directly or indirectly, by contractual commitment or otherwise, by foreign persons of any interest in property in the United States, or of stock, other securities, or short and long-term debt obligations of a United States person, and (b) the ownership or control, directly or indirectly, by contractual commitment or otherwise, by United States persons of any interest in property outside the United States, or of stock, other securities, or short- and long-term debt obligations of a foreign person.