EXHIBIT 99.1 CERTIFICATE OF THE CHAIRMAN OF THE BOARD AND CHIEF EXECUTIVE OFFICER OF HARKEN ENERGY CORPORATION (REGISTRANT) Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C.(S) 1350): I, Mikel D. Faulkner, Chief Executive Officer of the Registrant, certify to the best of my knowledge and belief pursuant to Section 906 of Sarbanes-Oxley Act of 2002 (18 U.S.C.(S) 1350) that: (1) The Quarterly Report on Form 10-Q for the period ended March 31, 2002, which this statement accompanies, fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2) The information contained in the Quarterly Report on Form 10-Q fairly presents, in all material respects, the financial condition and result of operations of the Registrant. Date: December 20, 2002 /s/ Mikel D. Faulkner ---------------------------- Chief Executive Officer