The official declined to provide details about the possible suspects, or in what countries they are being sought.
Law enforcement officials, through the use of an informant, were able to undermine the plot in its early stages.
The four suspects already in custody made trips to the airport, took video and photographs, drew diagrams and collected information. They then hoped to shop their information to individuals with the capacity to pull off their stated plan of causing "greater destruction than the September 11 attacks," the official said.
According to court documents, the men sought the help of Jamaat al Muslimeen, or JAM, a Muslim organisation based in Trinidad. The group staged a coup attempt in 1990, storming the Trinidad parliament building and taking the prime minister hostage.
Authorities said that if the men had won support from JAM or anyone else with the right resources, the plans could have been carried out in a short period of time.
But some experts have called the plot far-fetched, saying it would have been virtually impossible to achieve the kind of destruction the suspects envisioned.
Alleged mastermind Russell Defreitas, a US citizen from Guyana, hatched the plan when he worked as a cargo employee at JFK 10 years ago, authorities said.
He is being held in New York on conspiracy charges. His alleged co-conspirators, two citizens of Guyana and one from Trinidad, are in jail in Trinidad and were expected to fight extradition to New York.