The U.S. administration has already highlighted the statistic to lobby its NATO allies - with limited success - to commit more forces to Afghanistan - a conflict likely to test the West's stomach for a long, grinding war.
Marvin Weinbaum, a former State Department official and now an Afghan expert at the Washington-based Middle East Institute, said the rising casualties would sharpen the focus on Afghanistan in the U.S. presidential race.
"What's being brought home is the nature of the conflict. It's in the true fashion of a guerrilla operation and we're not prepared for it," Weinbaum said Saturday.
The Taliban's tactics have been changing - fewer direct confrontations with coalition forces and more roadside bombs, reports CBS News correspondent Mark Phillips.
A bold attack on a prison in which 350 Taliban fighters were freed earlier this month was another sign of the insurgency's growing confidence.
Afghanistan President Hamid Karzai says the insurgency is being organized out of border regions of Pakistan and is threatening to carry the fight back.
"Afghanistan has the right of self-defense when they cross the territory from Pakistan to come and kill Afghans and kill coalition troops. It exactly gives us the right to go back and do the same," he said.
Violence continues unabated, despite the more than 60,000 foreign troops in the country and fresh pledges of financial aid to Karzai's struggling government.
Last year, more than 8,000 people were killed in insurgency-related attacks - the most since the 2001 U.S.-led invasion - and violence has claimed more than 1,700 lives so far this year.
In Saturday's deadliest incident, a roadside bomb hit a coalition convoy west of the southern city of Kandahar, killing four troops and wounding two others.
Coalition spokesman Lt. Col. Paul Fanning said gunmen opened fire on the damaged vehicles and three Afghans were also hurt.
He declined to release the nationality of the troops, who were involved in training Afghan forces.
To the east, a Polish soldier from the separate NATO-led force died when a bomb hit his patrol after midnight in the Dila district of Paktika province. Jacek Poplawski, a Polish military spokesman in Warsaw, said four other soldiers were wounded.
The bombings capped a bloody week.
NATO and Afghan troops backed by warplanes on Wednesday attacked up to 400 Taliban militants who had seized the strategic Arghandab valley, within striking distance of Kandahar.
Lt. Gen. Sher Mohammad Karimi, chief of operations for the Afghan Defense Ministry, said Afghan troops had counted the bodies of 94 insurgents and were holding 29 suspects.
About three-quarters of the militants were foreigners, and villagers said they heard them speaking Arabic and Urdu - the main language of Pakistan, Karimi told reporters in Kabul.
A total of 31 foreign troops have died this month, including four British soldiers, four American troops and another member of the U.S.-led coalition killed earlier this week, according to an Associated Press tally.
In Iraq, where violence has decreased in recent months, 19 have died, though the 200 killed there so far this year is double Afghanistan's total.