But Lieutenant-General David Richards promised on Sunday that the incoming force would be more "people-friendly" in an effort to win the support of the local population amid rising resentment towards the US-led coalition over its aggressive tactics.
Speaking at a news conference in Kabul, Richards, a Briton who took command of Nato's International Security Assistance Force (ISAF) a month ago, said the coalition does not have enough troops in southern Afghanistan to deal with the violence.
"They have been relatively short of troops, of boots on the ground," he said.
He said the figure would increase from an average of about 3,000 in recent years to about 6,000 when ISAF assumes responsibility for the region next month.
The new force would also have more attack helicopters, he said.
The changeover comes amid the most intense fighting in the south since the Taliban government was overthrown in 2001. More than 400 people, mostly insurgents, have been killed since mid-May.
Observers in the south say support for the foreign troops has waned in recent months, partly because of a large number of civilians killed mistakenly in coalition operations and also because of an increased presence of Taliban fighters.
Observers in the south say support
for foreign troops is waning
Hamid Karzai, the president, has repeatedly complained about the allegedly overly aggressive tactics of the coalition and last year demanded an end to air strikes and house searches - but the coalition said they were essential and did not stop them.
Richards acknowledged that security had deteriorated, but said he was optimistic his tactics would counter that trend.
"I have a different approach," he said. "I want to get out much more on our feet in and among the villagers... We will gear our security operation around [building] more roads, irrigation, etc."
But he warned that when needed, the Nato force, which has troops from 36 nations, would be tough.
"When we need to be muscular, robust with those opposing us, we have all the capability we need and we will certainly do so," he said.
The US has raised its troops levels in Afghanistan in recent months from 18,000 to 23,000.
It is expected to start withdrawing some of those troops once ISAF takes over in the south. ISAF's troop levels for the whole country will jump from the current number of around 9,000 to about 17,000 by next month.
The move by Nato to take over in the south is part of a plan for the force to assume control of security across the country.