The US military said their troops suffered no casualties in the attacks in four provinces on Saturday and Sunday, but one resistance fighter was killed.
The attacks in Khost, Paktika, Nangarhar and Kandahar provinces follow the bloodiest period in Afghanistan since the overthrow of the Taliban in late 2001, in which more than 300 people have been killed since the start of August.
They came before Tuesday's anniversary of the start of US bombing of Afghanistan on 7 October 2001, and during a weekend visit by Deputy Secretary of State, Richard Armitage.
A statement from the US military said US-led forces conducting an offensive operation near their base at Khost were ambushed by small-arms fire on Saturday, but suffered no casualties.
On Sunday, a special forces unit on patrol near its base at Orgun-e engaged a 15-strong force, killing one of them in a 30-minute fight after coming under rocket-grenade and small-arms fire.
Elsewhere in the south, bases of US-led forces in Jalalabad and Kandahar came under rocket attack on Sunday, but the missiles caused no damage or casualties.
Hamid Karzai is the only Pashtun
member of government
On Sunday, the Afghan government and the United States played down the upsurge in Taliban attacks in recent months, with Armitage saying recent activity showed the fighters were "frightened".
Afghan Foreign Minister, Abd Allah Abd Allah, said Afghanistan still had problems with security, but the incidents that had occurred often presented a false picture of the overall situation.
He said there had been great improvements since two years ago, when Taliban-ruled Afghanistan was the centre of global destabilisation and home to al-Qaida.
However, Aljazeera's correspondent in Afghanistan says the country's Pashtun-majority, which is based in the south and east, remains disgruntled because of a lack of political representation.