Bureau of Corrections director Vicente Vinarao said they will be treated as ordinary inmates and will not enjoy special attention.
"We already have 11 Americans here at the maximum security compound. They will be placed in the same detention area," he told The STAR.
Vinarao said detention prisoners receive equal treatment regardless although there are designated cells for US nationals.
Judge Benjamin Pozon is scheduled to issue a verdict on the Subic rape case Nov. 27 after four months of marathon hearings.
Lance Corporals Daniel Smith, Keith Silkwood, Dominic Duplantis, and Staff Sergeant Chad Carpentier of the US Marine Corps are accused of raping a 23-year-old Filipina, nicknamed "Nicole" by the media.
Pozon will issue his decision exactly a month before the deadline by which American soldiers can be tried in a Philippine court which will expire under the Visiting Forces Agreement (VFA) on December 27, 2006.
If acquitted, the four American soldiers who are now being held at the US embassy will finally be allowed to leave the country.
But if convicted, the court is expected to immediately order them sent to the national penitentiary.
Vinarao said those sentenced to spend 20 years in prison or more go to the maximum security section while those with shorter sentences go to the medium security section.
But before convicted felons are sent to a cell, they will have to spend two months at the Research and Diagnostics Center first.
Vinarao explained that new inmates go through two months of training, check-ups, briefings and other screening procedures.
"It is there that they undergo training, medical tests, psychological tests, psychiatric examinations, and briefings," he said.
Vinarao said it is at the diagnostics center that prison authorities will determine if a person is fit to be detained in the facility or if one needs medical attention.
He added that it is also at the RDC that new inmates are given their designated serial numbers after all information about them and their case are put together in a folder for a dossier.
"There will be no VIP treatment. They will be treated as ordinary inmates and will go through ordinary procedure," he said.
Vinarao took note of how diplomatic officials from other countries look after the welfare of their nationals who are in prison, often to check if they are in good condition.
The rape case sparked angry calls for the scrapping of the Visiting Forces Agreement, a 1999 accord between Manila and Washington that allows large-scale US military exercises in the Philippines.
It also allows American troops who are charged with crimes to remain in US custody until legal proceedings are completed.
The rape case is seen as a black mark on the US military exercises that have been credited with helping weaken al-Qaeda-linked militants in the southern Philippines.
The US embassy has refused to turn the Marines over to Philippine authorities, citing a provision under the VFA. However, the US decision infuriated many, including many lawmakers, and set off small but noisy anti-US street protests.
The four Marines belong to the 31st Marine Expeditionary Force stationed in Okinawa, Japan, and had finished counterterrorism maneuvers with Philippine troops in Zambales.
They were on shore leave when the alleged rape occurred on Nov. 1 inside a van at the former US Subic Bay naval base close to Olongapo City after the woman went with one of the soldiers on a bar hop.
The soldiers had insisted only one of them, Smith, had sex with her and that the act was consensual.