U.S. deaths in Afghanistan increased threefold during the first two months of 2009 compared with the same period last year, after thousands more troops deployed and commanders ramped up winter operations against an increasingly violent insurgency.

As troops pour into the country and violence rises, another sobering measure has also increased: More Afghan civilians are dying in U.S. and allied operations than at the hands of the Taliban, according to a count by The Associated Press. In the first two months of the year, U.S., NATO or Afghan forces have killed 100 civilians, while militants have killed 60.

President Barack Obama recently announced the deployment of 17,000 additional troops to bolster 38,000 already in the country, increasing the U.S. focus on Afghanistan while a drawdown begins in Iraq. The latest casualty toll among U.S. forces could portend a deadlier year in Afghanistan than the U.S. military has experienced since the Taliban's ouster in 2001.

"I think that because you are going to see that additional engagement, there is a risk of greater additional casualties in the short term, just as there was in Iraq," Obama told the Pentagon Channel on Friday from Camp Lejeune, North Carolina. "That is something we will have to monitor very carefully."

Twenty-nine U.S. troops died in Afghanistan the first two months of 2009 — compared with eight Americans in the first two months of 2008.

Part of the increase is due to the influx of troops. In early 2008 there were about 27,000 forces in the country, some 10,000 fewer than today.

But U.S. troops are also operating in new, dangerous areas. A brigade of 10th Mountain Division soldiers deployed in January to two insurgent-heavy provinces outside Kabul — Wardak and Logar. And American forces are increasingly operating in Taliban heartland in the south.

"It has a lot to do with the fact that we have a presence in places and going into places and disrupting insurgents in area where they haven't been bothered much," Col. Greg Julian, the top U.S. spokesman in Afghanistan, said Saturday. That, he said, means more battles and more attacks.

American troop deaths occurred at a much higher rate in Afghanistan than in Iraq in January and February. Thirty-one U.S. forces have died in Iraq so far this year, but there are roughly 140,000 American troops in Iraq, more than three times the number in Afghanistan.

The decreasing U.S. death toll in Iraq coincides with an overall decline in violence largely attributed to a cease-fire by anti-U.S. cleric Muqtada al-Sadr and a Sunni decision to join forces with the Americans against al-Qaida in Iraq.

Julian said that troops in Afghanistan have "maintained the pressure throughout the winter months" this season, though in previous years there had been a lull.

About a third of the 29 deaths this year were caused by roadside bombs, including an attack in Kandahar province on Tuesday that killed four U.S. troops. Julian said insurgents are using more IEDs and fewer direct attacks because militants die in large numbers when they fight the U.S. head on.

The number of other NATO soldiers killed so far this year has risen as well, but not at the same rate. Last year 13 soldiers from other NATO countries died in January and February, compared with 18 in the first two months of 2009. Of those 18 deaths, 12 were British.

Gen. David McKiernan, the top U.S. and NATO commander in the country, said he thinks Taliban militants are "resilient" but not necessarily stronger.

"I'm not with the group that says everything is in a downward spiral, that the Taliban are resurgent and stronger than they were. I think they're very resilient, but I don't necessarily think they're stronger," McKiernan told the Chicago Tribune in an interview published Friday.

"And I do see some measures of progress in this country. Now I'm not going to say everything is going to improve dramatically in 2009, but I think as a military commander, I am not going to be pessimistic about this. I'm going to be glass-is-half-full."

Violence in all categories is up in general so far this year. Militant deaths rose from 129 in early 2008 to 308 in early 2009, according to numbers compiled by The Associated Press based on figures from U.S., NATO and Afghan officials.

Civilian deaths from U.S. and NATO operations have also spiked, despite increasingly emotional pleas from Afghan President Hamid Karzai to address the problem.

Last year the Taliban set off several large suicide bombs in crowded areas, killing around 180 Afghan civilians the first two months of the year, while U.S., NATO or Afghan forces killed fewer than 10.

But the numbers have reversed this year. In the first two months of 2009 some 100 Afghan civilians have been killed by U.S., NATO or Afghan forces, according to the AP count, many during overnight missions by Special Operations Forces. Militants have killed about 60.