The trend of lower casualties among international forces is likely to continue this year as the NATO troops move increasingly into advisory and training roles.

U.S. troops in Afghanistan currently number about 66,000. Then-Defense Secretary Leon Panetta said in February that more than 60,000 would remain through the fighting season. By November, though, the number will drop to about 50,000 and nearly half will be gone in a year. The U.S. combat mission is expected to finish up by the end of 2014.

The Afghan security forces are expected to take the lead in combat everywhere in the country by this spring, President Barack Obama said in January.

Nearly 2,200 U.S. troops have been killed and more than 17,000 wounded since fighting began here. More than 1,000 troops from other nations in the coalition have been killed.

The peak of 499 American deaths came in 2010, along with the peak in U.S. troops here, after Obama order a “surge” of about 30,000 troops that brought the total to about 100,000.

Casualties began dropping after that. Last year, the number of U.S. troops killed was 310.

More civilians are killed in the fighting than either ISAF or Afghan security forces. Last year, the toll was more than 2,700, according to a recent United Nations report. That was down slightly from the previous year, but there were more killings in the last half of the year compared with the same period in 2011. More women and girls fell victim last year, too, with a 20 percent jump, to 301 killed and 563 wounded.

Most of the civilian deaths were caused by insurgents, according to the report, which also said such killings by the international forces had dropped by nearly half last year.