Fighting erupted near Shkin in the eastern province of Paktika, where at least one other soldier was injured, said US Central Command in a statement on Sunday.
The names of the dead and injured troops are being withheld pending notification of next of kin, say US officials.
Throughout the day fighting raged in the southern rugged part of the country near Bermil village by the Pakistan border. US fighter jets and helicopters pounded suspected Taliban hideouts.
Earlier this year US special forces sent a laser guided missile into a home in Bermil believing it to be a Taliban stronghold. Instead 11 children were wiped out in the blast which demolished a family home. One woman, who survived, lost all her nine children.
Zabul province in southern Afghanistan has been the scene of intense fighting for over a week now with Afghan government and US forces claiming to have killed more than 100 Taliban fighters.
Six Afghani troops were killed and four were wounded when Taliban fighters attacked three Afghani government cars in the Tazi area on the main road in Zabul province, Aljazeera’s correspondent in Afghanistan reported.
Four Afghani troops were arrested and then released by the Taliban fighters.
Around 50 Taliban fighters carried out the attack, the four released troops said.
US-led forces toppled the ruling Taliban in October 2001. Since then an international force led by American troops have remained in the country searching out remnants of the group.