KABUL/WASHINGTON (Reuters) - A U.S. soldier was killed in fighting in Afghanistan, a senior U.S. general said on Thursday, bringing the American combat death toll this year to seven service members.

U.S. General Joseph Votel, speaking to Pentagon reporters in Washington, declined to offer details, citing the need to notify the soldier’s family. The Pentagon says there are about 14,000 U.S. service members in Afghanistan. More than 2,400 U.S. forces have died in the 17-year-old war, America’s longest conflict.

The U.S. military’s mission is focussed mainly on guiding and aiding Afghan forces battling the Taliban, which was ousted from power in 2001.

President Donald Trump has expressed scepticism about America’s involvement in the war. Critics warn his military cannot promise to defeat the Taliban anytime soon or overcome Afghanistan’s vast political divisions and entrenched corruption.

Although Trump administration officials emphasise efforts to broker a peace agreement with the Taliban, many U.S. officials are not sure a meaningful deal can be reached as long as the Taliban believe they are in a relative position of strength.

U.S.-backed Afghan forces, meanwhile, have sustained heavy losses fighting the Taliban. Votel said he believed the number of Afghan military casualties had risen this year against last year, despite increasing U.S. support under Trump.

“It is my understanding that it (the number of Afghan casualties) is increasing,” Votel said.

Votel compared of the Afghan force to a soldier with a bloody nose, who was still standing and fighting.

“That’s exactly what they’re doing right now. So they are able to sustain this,” he said.