Dear David Guerrero,
Thank you for posting your question to History Hub!
The best place to start your search would be in Record Group 84: Records of the Foreign Service Posts of the Department of State, 1788 - ca. 1991, specifically, the Unclassified Central Subject Files, 1964 - 1975 created by the U.S. Embassy in Manila (https://catalog.archives.gov/id/4477995 ). Unfortunately, it appears that these records are not currently available online.
For more information on this series, you may contact Archives2reference@nara.gov.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this information is helpful. Best of luck with your research!