Without giving a date for the trials, the Pentagon told news organisations that the accreditation of journalists for the tribunals had to be sent by 17 February.
Most of the 660 Guantanamo detainees were captured in Afghanistan as part of President George Bush's "war on terror" after the September 11 attacks.
However, the United States has refused to classify them as prisoners of war.
In November, Bush designated six detainees who would be first to be tried. Two Yemenis, an Australian and a Sudanese have been assigned lawyers.
Clients not charged
Lawyers have said that their clients have not been charged.
"It is possible that one or more enemy combatants suspected of having violated the laws of war could face trial by military commission," said the department.
"To the extent possible, the Department of Defence intends to open the proceedings for media coverage," it said.
"If conducted, these proceedings will most likely take place at the US Naval Base in Guantanamo Bay, Cuba."
The Pentagon plans to accredit US and foreign news media, based on their importance in terms of audience.