One US troop was killed and two wounded in fighting Tuesday in Afghanistan's southern province of Helmand, the US military command in Kabul said.

The fighting, which reflects intensified efforts by the US and its Afghan partners to push back against recent Taliban gains, was near the city of Marja, in the restive province that shares a border with Pakistan.

The Taliban in recent weeks have focused their efforts on retaking parts of Helmand, and the US has countered with special operations forces working with Afghan troops.

Details on the battle were sketchy.

In a brief written statement announcing the three US casualties, the US military command in Kabul said one died of wounds sustained "during operations" in Marja, and that two were wounded.

"We are deeply saddened by this loss," said Brig. Gen. Wilson A. Shoffner, a spokesman for US forces in Afghanistan. "Our heartfelt sympathies go out to the families and friends of those involved."

The identity of the casualties has not yet been revealed. Two US officials said they were special operation troops.

A US helicopter was sent to evacuate the casualties but did not immediately take off because of an unspecified problem.

Some reports in US media said the helicopter had also come under fire.

In Kabul, a spokesman for the US military confirmed it had landed, but said it had experienced "mechanical malfunctions".

"It was not shot down. It intentionally landed safely," he said.

(FRANCE 24 with AP)