In a direct election-year challenge to US President Barack Obama on national security, lawmakers unveiled legislation Thursday requiring military interrogations and trials for suspected terrorists.

The "Enemy Belligerent Interrogation, Detention, and Prosecution Act of 2010," introduced in both the Senate and House of Representatives, also says suspects should not be told they have a right to remain silent.

"Needless to say, we are at war, this bill recognizes that," Republican Senator John McCain, a lead author of the measure, told reporters.

"These are not common criminals, they are war criminals," said Independent Senator Joe Lieberman.

"Anyone we capture in this war should be treated as a prisoner of war, held by the military, interrogated for information that will protect Americans and help us win this war and then, where appropriate, tried not in a normal federal court where criminals are tried but before a military commission," he added.

The bill comes amid a fierce election-year battle over how the United States should handle alleged extremists, with Republicans attacking President Barack Obama over the treatment of the so-called Christmas Day plotter.

Republicans have denounced the decision to have civilian authorities detain and question Umar Farouk Abdulmutallab, the 23-year-old Nigerian accused of trying to use explosives sewn into his underwear to blow up a Northwest Airlines plane with nearly 300 people aboard.

Abdulmutallab, who US officials say has provided valuable intelligence under civilian questioning despite being told he had the right to remain silent, was allegedly trained by an Al-Qaeda affiliate in Yemen.

Republicans have also denounced the Obama administration's call for trial in a civilian court of Khalid Sheikh Mohammed, the self-proclaimed mastermind of the September 11, 2001 attacks.

Democrats have shot back that US civilian courts have successfully tried and convicted scores of terrorists and that pushing for military trials gives extremists a propaganda victory by enhancing their stature.

The new legislation aims to require high-risk "unprivileged enemy belligerents" to be held in military custody and interrogated "for their intelligence value" by a specialized "High-Value Detainee Interrogation Team."

It would aim to block civilian trials for such suspects by forbidding the use of US Department of Justice funding for that purpose, according to a summary of the bill provided to AFP.

The legislation says the "high-value detainees" shall not be given a so-called "Miranda warning" -- including the right to remain silent -- that US authorities are normally required to read to suspects upon arrest.

The bill says a suspect will be labeled "high-value" if they pose a threat of attack on civilians or civilian facilities on US soil or overseas, or to US military personnel or facilities; have "potential intelligence value;" or belong to Osama bin Laden's Al-Qaeda network or an affiliate.

"This bill aims to correct the president's mishandling of a major aspect of the ongoing war on terror," said Representative Buck McKeon, the top Republican on the House Armed Services Committee, who accused Obama of "relaxing our detainee policies."