"All of Arghandab is made of orchards. The fighters can easily hide and easily fight," he said.
"It is quite close to Kandahar. During the Russian war, the Russians didn't even occupy Arghandab, because when they fought here they suffered big casualties."
The Taliban offensive follows the escape of more than 1000 Taliban and other prisoners in a suicide attack on the main jail in the southern city of Kandahar on Friday night, which also left many prison guards dead.
Mark Laity, a Nato spokesman, said that Nato and Afghan military officials were redeploying troops to the region to "meet any potential threats".
"It's fair to say that the jailbreak has put a lot of people [fighters] into circulation who were not there before, and so obviously you're going to respond to that potential threat," he said.
Al Jazeera's Hashem Ahelbarra, reporting from Kandahar, said that hundreds of Taliban fighters are taking up positions in the area and taking over nearby villages.
"Ultimately, it is local residents who are paying a heavy price for this increasing instability," he said.
"The Taliban are showing impressive capability in manoeuvring in and around the area."
In other violence in Afghanistan, a 12-year-old child was killed by a roadside bomb, while a baby and a woman have been wounded in an air raid by US-led forces in the east of the country.
An interior ministry statement said on Monday the student was on his way to school in the Yaqoubi district of eastern Khost province when he was killed a day earlier.
A roadside blast also struck an Afghan army vehicle in the Girishk district of southern Helmand province on Sunday, wounding two soldiers, police said.
In the US-led air raid against Taliban fighters in the Arghandab district of southern Zabul province, two armed men were killed, police said.
"Coalition aircraft targeted a Taliban position as part of the same operation which wounded a woman and a child," police said.
Both wounded were receiving treatment in hospital, he said.
The violence came after Hamid Karzai, the Afghan president, sparked a major row with neighbouring Pakistan by threatening to launch attacks on fighters allegedly hiding in Pakistani territory.
The Taliban have stepped up an insurgency against Karzai's US-backed government since being removed from power in late 2001, resulting in the loss of thousands of lives.