The incident, captured in a video posted online that depicts American troops desecrating the bloodstained corpses of fighters, has appalled Afghanistan's President Hamid Karzai and embarrassed the Pentagon.

"These kids made a mistake, there's not any doubt about it," Perry, the governor of Texas who is trailing most of his rivals in the battle for the Republican nomination for the November election, told CNN.

"But the idea that this administration would go after these young people for a criminal act is, again, over the top."

The US military has launched a high-level investigation and the four Marines have been questioned, while US Defense Secretary Leon Panetta and Secretary of State Hillary Clinton have both expressed dismay at the acts and vowed that the culprits would be punished.

There are concerns that the video could be used as a recruiting tool for the Taliban and anti-American insurgents.

Perry, a former US Air Force pilot, criticized what he described as President Barack Obama's administration's "disdain for the military... whether it's the secretary of state or whether it's the secretary of defense.

"Did (the four US Marines) make a mistake? Absolutely. Should they be reprimanded and appropriately punished? Yes. But going after them as a criminal act I think sends a really bad message."

Perry recalled how World War II era US general George Patton famously urinated in the Rhine river during his troops' march into Nazi Germany, and, "although there's not a picture, (British prime minister Winston) Churchill did the same thing on the Siegfried Line" to show contempt for the Nazis.

The US military said the four Marines are from a sniper unit in the 3rd Battalion, 2nd Marines based at Camp Lejeune in North Carolina, and they were grilled by the Naval Criminal Investigative Service which is leading a criminal inquiry into the affair.

The unit was deployed in southwestern Afghanistan's Helmand province from March to September last year, and the video "potentially" was shot during that period, a military official told AFP.

Court sessions were to be held by the Supreme Court on a long-running Swiss corruption case chiefly against President Asif Ali Zardari, and by a commission set up to probe the scandal that has become known as "Memogate".

The memo scandal centres on an unsigned note allegedly sent by an aide of Zardari to the American military last May, seeking help in stopping a possible coup following the covert killing of Osama bin Laden in Pakistan by US Navy SEALS.

The commission, set up on December 30 and encouraged by the country's top intelligence officer, is to hear from the government in Islamabad on Monday morning and should return its findings later in the month.

It will decide whether the government endorsed the note, and if so, if it can remain in power.

The Supreme Court will also meet to decide how to proceed on graft charges against Zardari and other lawmakers, who claim to have amnesty from prosecution in the case.

After a smaller panel of judges failed to reach a decision last week, a larger bench will convene to debate six options for dealing with the leaders, which include dismissing the prime minister and holding early elections.

In the afternoon the National Assembly, the country's legislative body, is to vote on a resolution tabled by a minor coalition party in a bid to bolster the civilian leadership amid a simmering row with the powerful army.

Tensions between civilian leaders and the army came to a head last week when Prime Minister Yousuf Raza Gilani accused top brass of failing to submit statements to the Memogate commission through government channels and later sacked his defence secretary -- a retired general.

The army issued a terse statement that warned of "potential grievous consequences for the country" and the row provoked fears of another coup in the country that has spent half its existence under military rule.

But political and defence analysts believe that the military has no appetite for a coup and would prefer to see the leaders removed by legal means.

Gilani moved over the weekend to calm mounting tensions between the government and armed forces, telling a meeting of the cabinet defence committee: "The armed forces of Pakistan are a pillar of the nation's resilience and strength. The nation applauds their heroic services in the defence of the motherland."

The meeting, in which Gilani called for national unity, was attended by army chief General Ashfaq Kayani, widely regarded as Pakistan's most powerful figure, as well as several other top military officials.