As of Wednesday, at least 46 international troops, including 24 Americans, had been killed in Afghanistan this month, according to statements by the U.S. military and the NATO command. That matches the tolls for the two previous deadliest months - June and August of 2008.
The rate of deaths in July - about three a day - is approaching some of the highest levels of the Iraq war.
The latest reported deaths occurred Tuesday. They include an American soldier who was killed by a roadside bomb in eastern Afghanistan and two Turks, including a colonel, who died in a traffic accident in the north of the country.
In addition, six Ukrainian civilians and a 6-year-old Afghan were killed Tuesday when an Mi-6 transport helicopter crashed in southern Afghanistan. The helicopter's owners in the former Soviet republic of Modova said the helicopter was shot down, and the Taliban claimed responsibility.
In Washington, Pentagon spokesman Geoff Morrell acknowledged that the U.S. has lost troops "at an alarming rate this month."
He told reporters that July has been "an extraordinarily difficult month for all of us who are so heavily invested in trying to better the situation in Afghanistan."
U.S. commanders have been expecting higher casualties since President Barack Obama ordered 21,000 additional U.S. troops to Afghanistan this year to curb a resurgent Taliban that threatens not only the U.S.-backed Kabul government but also Afghanistan's nuclear-armed neighbor, Pakistan.
There are about 57,000 U.S. troops currently in Afghanistan, and the number is expected to rise to at least 68,000 by the end of 2009.
Obama's decision has effectively shifted the focus on the global war against Islamic extremism from Iraq, where the United States still maintains about 130,000 troops. Only two U.S. service members have died in Iraq this month - both from non-hostile causes, according to the Pentagon.
With the increase in troops heading for Afghanistan, the U.S. has stepped up the tempo of combat operations. About 4,000 U.S. Marines this month launched their biggest offensive since 2001 to break the Taliban stranglehold on the southern province of Helmand, the center of the country's opium poppy cultivation and a major insurgent smuggling route from Pakistan.
British forces, meanwhile, have been locked in fierce combat with Taliban fighters in another part of Helmand. Britain's 9,000-strong military force has lost 15 soldiers this month - including eight in a 24-hour period. Those deaths have prompted national debate in Britain over whether the Afghan conflict is winnable.
For their part, the Taliban have increased their attacks, including deadly roadside or suicide bombings that rose by 25 percent in the first four months of 2009 over the same period last year. The U.S. command expects bombings to rise 50 percent this year to 5,700 - up from 3,800 last year.
Other deaths this month among international forces include four Canadian soldiers and one Italian paratrooper.
British Prime Minister Gordon Brown said this week that international troops in Afghanistan face a difficult summer of intense fighting. He has long called on other NATO allies, and European nations, to play a larger role in combat operations in Afghanistan and insisted that the Afghan army should provide larger numbers of soldiers.
The Afghan government provided only about 650 soldiers and police to join the ongoing Marine offensive in Helmand.
During a visit to Helmand on Wednesday, the outgoing chief of the British army, Gen. Richard Dannatt, said the international mission needs more soldiers to control territory won from the Taliban to give Afghans more confidence in security and wean them away from the Taliban.
"I have said before, we can have effect where we have boots on the ground. I don't mind whether the feet in those boots are British, American or Afghan. But we need more, to have the persistent effect to give the people confidence in us," Dannatt told BBC radio from the British base in the Helmand town of Sangin. "That is the top line and the bottom line."
The U.S. is sending thousands more soldiers to train Afghanistan's police and army.
Obama said Tuesday that he hopes military operations in Afghanistan can move to a different phase after the Afghan presidential election set for Aug. 20. Obama said he is looking for an exit strategy in which the Afghan army, police, courts and government take more responsibility for the country's security.
During last year's election campaign, Obama accused President George W. Bush of diverting U.S. resources from the war in Afghanistan, where al Qaeda's leadership planned the Sept. 11, 2001 attacks in New York and Washington, to what he termed an unnecessary war to oust Saddam Hussein in Iraq.