San Juan, Puerto Rico (CNN) The government of Puerto Rico on Thursday announced it has enlisted George Washington University to review deaths that followed Hurricane Maria.

The official death toll after the September 20 storm stands at 64 -- but reports from CNN and others suggest the actual number of deaths may be significantly higher, perhaps more than 1,000.

"I want to know the truth," Puerto Rico Gov. Ricardo Rosselló said during a press conference at the governor's mansion, La Fortaleza. "Our objective is that clarity comes to the situation," he added. "It's important for those that have lost loved ones -- and everyone in Puerto Rico -- (to) know close to the exact number of deaths (that were) due to the storm."

One aim of the review, officials said, is to estimate the number of "excess deaths" that followed the storm, a statistical measure that compares the number of deaths following the storm to those that occurred during the same time frame during the previous years. Researchers also plan to investigate individual cases, including interviewing family members of the dead.

A draft report, to be released in three months, will include a statistical estimate of the number of hurricane-related deaths between the storm and the end of February 2018, said Lynn Goldman, dean of the Milken Institute School of Public Health at George Washington University in Washington, DC. A peer-reviewed report on hurricane deaths -- including interviews with families, hospitals and funeral homes -- will be released in one year, she said. That report also will include a review of the Puerto Rican government's handling of the count.