"Security remains a serious problem in Iraq partly because, contrary to administration assurances, our military force levels are obviously inadequate," Republican Senator John McCain wrote in The Washington Post on Sunday.
"We need more foreign troops, particularly from Muslim allies such as Turkey and Pakistan," he said, adding that "it is the number and quality of military forces, not the number of countries that send them, that matters."
The rising US casualties have caught Americans' attention this week, as the number of soldiers killed during the occupation topped the number killed during the war.
According to Pentagon figures, a total of 78 US soldiers have died in circumstances officially unrelated to combat in Iraq since Bush declared major operations over on 1 May. Another 65 US soldiers have been killed in guerrilla attacks during that period.
"This is taking its toll, I think, on the American attitude toward what we're doing there," Senator Richard Durbin told ABC.
"We need more foreign troops, particularly from Muslim allies such as Turkey and Pakistan"
"I hope the Bush administration will have a change of heart and a change of direction and start bringing in troops from other nations, so that American soldiers can be safer, and other American soldiers can come home."
Unease about the Iraqi conflict was also reflected in a British newspaper survey published on Monday, which showed more than 60% of Britons in favour of withdrawing their soldiers.
A pullout is backed by 61% of Britons, with 29% saying the troops should return home as soon as possible, according to an ICM poll published in The Mirror newspaper.
Another 32% said the British soldiers should leave Iraq "gradually but with a final date set", while a similar number said they should "stay as long as necessary".
The poll was carried out afterthe British Prime Minister, Tony Blair, appeared on Thursday before an inquiry, headed by British judge Lord Hutton into the apparent suicide of David Kelly, 59, a former UN arms inspector in Iraq.
Shias mourn al-Hakim, denounce
In Iraq itself, thousands of Iraqis continued to pay their respects to top Shia cleric Ayat Allah Muhammad Baqir al-Hakim, as the funeral procession continued for the second day.
Mourners from across Iraq and neighbouring Iran began filing into the al-Abbas shrine in the mainly Shia city of Karbala on Monday to pay their final respects.
Al-Hakim died on Friday in a car bomb attack in Najaf that left at least 82 others dead and 125 wounded.
Friday's bombing in Najaf has fuelled the anger of Iraq's Shia community who make up about 53% of the population, but who were oppressed by Saddam's Sunni elite.
Two Saudi citizens have been arrested after the Najaf attack, when they sent an email saying “mission accomplished: the dog is dead”.
The men were grabbed by a crowd in Najaf on Saturday, the day after the bombing and taken to a police station after being seen sending the mail from an Internet café, an anonymous source was quoted by a London-based newspaper as saying.
The two suspects apparently attracted the attention of the son of the café owner after having “offered a larger than usual sum of money to use a computer,” said the British daily on Monday.
It was then that the son saw the men send a message saying, “mission accomplished: the dog is dead”.