The fighting has killed more than 500 people, mostly militants, since May.
Defense Minister Abdul Rahim Wardak said the rebels have stepped up attacks to try to discourage NATO from deploying troops there.
Meanwhile, a U.S.-led coalition soldier and seven Afghan civilians were killed in the latest violence in the south.
Speaking to a group of eastern Afghan tribal elders, President Hamid Karzai on Sunday contested media reports that he was considering forming militias, amid fears that doing so could lead to clashes between rival tribes.
"We don't want to form militias," Karzai said. "We just want to strengthen the districts to safeguard them from terrorist attack."
He said tribal recruits would take their orders from the government.
Karzai's spokesman, Karim Rahimi, called them "community police."
"For the last four years, what the United States and it's allies are trying to do in Afghanistan is disarm everybody," CBS News Analyst Jere Van Dyk said. "Because that country, like Iraq, is awash with arms."
Wardak, the defense minister, acknowledged that southern violence had risen, but said it was just an all-out Taliban push to scare Britain, Canada, the Netherlands and Romania away from plans to deploy about 6,000 troops to the region as part of a NATO force.
They are expected to resume responsibility for the region from the coalition next month.
"They just want to take advantage of this period of transition from coalition to NATO, and they want to have maximum impact," Wardak said.
He said that once NATO deploys extra troops - effectively doubling the number of foreign combat forces - and the government sends more soldiers there, "I am absolutely sure that the situation will improve drastically."
On Sunday night, U.S. Army Brig. Gen. Mark Kimmitt, former command spokesman in Iraq, said on CNN's "Late Edition" that he thought the Taliban "is trying to make a comeback."
"And what they're finding is that their thought that, somehow, the NATO troops ... weren't going to stand and fight - I think they found that is not the case," Kimmitt said.
"The Canadians have demonstrated that they're willing to fight as hard and as well as the U.S," he said. "And the British, of course, always do."
The coalition said Canadian and Afghan troops recently battled about 60 rebels in Zabul province, leaving about 30 militants dead.
In the latest violence, a U.S.-led coalition soldier was killed Sunday when a bomb hit his armored vehicle during a search of a Ghazni province village, a U.S. military statement said.
U.S. military spokesman Sgt. Chris Miller said he could not disclose the soldier's nationality.
Also in Ghazni, unidentified gunmen killed three Afghans Saturday as they drove near the provincial capital, said local police commander Ali Ahmad.
In nearby Kandahar province, gunmen killed four Afghan laborers working for an Indian road construction company, said Daod Ahmadi, a government spokesman. About 400,000 afghanis (US$8,000; euro6,350) was stolen from them. It was not immediately clear whether Taliban or thieves were responsible.