The Nato-led peacekeeping force in Afghanistan will expand to cover the whole country by the end of 2006, a senior alliance commander has said.
Command of the Nato force rotates every six months
The move is part of Nato's plan to take charge of security in areas outside the capital, Kabul, where US-led coalition forces currently operate.
The announcement came as a new Italian unit took command of the Nato-led peacekeeping mission in Afghanistan.
Afghan parliamentary polls take place in six weeks amid major security fears.
On Thursday, one US soldier was killed and another wounded by a bomb in Paktika province. An Afghan soldier was also hurt.
In Zabul province a member of the Afghan security forces was killed in an attack by suspected Taleban militants.
The 8,000-strong International Security Assistance Force (Isaf) is currently largely concentrated in Kabul, with smaller units in northern and western areas where security has been less of a problem.
Gen Gerhard Back, commander of the Nato division responsible for Isaf, said his peacekeeping troops would be seeking "more robust" rules of engagement.
They would be deployed in eastern as well as southern areas, where Taleban-led violence is concentrated, and across the entire country by the end of next year, he told reporters in Kabul.
The US military has been keen for Nato to move into these more difficult areas of Afghanistan, in the hope that it can start withdrawing its own troops.
But this kind of expansion has proceeded slowly until now.
Only Canada has begun the process of deploying troops to Kandahar in the south.
Plans are under way for Isaf to move outside its Kabul base
By the middle of next year Nato will be in charge of the south, and by the end of the year in charge of all 34 provinces in Afghanistan, Gen Back said.
According to the BBC's Andrew North in Kabul, the main concern for Nato will be finding the extra soldiers to deal with the security challenges.
Many Afghans had called for the expansion of the international security operation straight after the fall of the Taleban in late 2001, but at that stage the US was opposed.
It is now far harder to get Nato countries to commit more troops, our correspondent says.
Nato is sending an extra 2,000 troops ahead of September's parliamentary elections but they are likely to be withdrawn soon afterwards.
More than 30 nations contribute troops to Isaf, which was placed under the control of Nato in August 2003.
For the past six months Nato member Turkey has led the force, command of which changes every six months.
This time it is being taken over by one of five rapid reaction units in Nato.
Most of its troops are Italian, including the commander. But his deputy is British.
Maj Gen Roger Lane led a Royal Marine force sent to Afghanistan in 2002 to hunt remnants of al-Qaeda and the Taleban.
The main threat to Afghan security still comes from al-Qaeda and the Taleban - who have been blamed for an upsurge in violence this year that has claimed hundreds of lives.