On April 30, 1999, Mr. Marvin Roy Feldman Karpa (the Claimant) filed, with the Secretary-General of the International Centre for Settlement of Investment Disputes (ICSID or the Centre), a Notice of Arbitration against the United Mexican States (the Respondent or Mexico) under Chapter Eleven of the North American Free Trade Agreement (NAFTA), and, simultaneously, sought approval of access to the Additional Facility of ICSID as foreseen under NAFTA Article 1120.