Kabul ? Five U.S. troops died in attacks in southern Afghanistan, military officials said Friday, adding to this year’s record death toll as American public support is dwindling for operations in the country that once hosted Osama bin Laden.

The Obama administration is debating whether to add still more troops to the 21,000-strong influx that began pouring into Afghanistan over the summer. Most of those have gone to the south, where they’ve been assailed by roadside bombs and ambushes as they battle to take back Taliban-controlled areas.

The commander of U.S. and NATO forces, Gen. Stanley McChrystal, told “60 Minutes” that the strength of the militant group took him by surprise when he arrived this summer.

“I think that in some areas that the breadth of the violence, the geographic spread of violence, is a little more than I would have gathered,” he said in the interview to be broadcast on Sunday.

This has been the deadliest year for American troops since the 2001 invasion to oust the Islamic extremist Taliban. The five deaths announced Friday bring to 214 the number of troops killed so far this year, well ahead of the 151 who died in all of 2008.

Four soldiers died Thursday in the same small district of southeastern Zabul province. Three were killed when their Stryker vehicle triggered a bomb in its path, and the fourth was shot to death in an insurgent attack, said U.S. military spokesman Lt. Robert Carr.

Meanwhile, a U.S. Marine was fatally shot while on foot patrol in southwestern Nimroz province, said Capt. Elizabeth Mathias, a military spokeswoman.