Peacekeepers have helped restore order to Kabul

They did not say which countries had offered to send more troops.

Nearly 6,000 Nato troops are stationed in the capital Kabul, while other Afghan cities are policed locally.

Police are on the alert for anti-war protests in the German city which also hosts a security summit this weekend, attended by many of the same ministers.

No timetable

The outgoing deputy commander of Nato forces in Afghanistan, Canadian Major-General Andrew Leslie, said in Kabul that Isaf should expand its force to up to 12,000 troops in order to maintain security.

He also said that Nato forces could be in the country for up to 10 years.

The alliance is well.....it is alive and it's kicking Jaap de Hoop Scheffer Nato Secretary General

Nato's Secretary General Jaap de Hoop Scheffer said a number of countries had offered to deploy additional so-called "provincial reconstruction teams" in Afghanistan, as part of the International Security Assistance Force (Isaf).

But he gave no timetable for the deployment or any indication about the numbers involved.

He said that despite a difficult year because of the conflict in Iraq, he said: "The alliance is well... it is alive and it's kicking."

Earlier Nato had played down German media reports this week that Isaf would be expanded to about 14,000 troops.

US Defence Secretary Donald Rumsfeld stressed that the existing mission should be made as effective as possible before any more soldiers were dispatched.

"I think Nato's... first task is to do well the Afghan task," he said.

"The next step might be for them to take on a somewhat larger role in Afghanistan."

Mr de Hoop Scheffer has previously suggested closer ties between Isaf and the 12,000-strong US-led combat force deployed elsewhere in the country.

Iraq issues

In Munich, Mr Rumsfeld played down continuing differences within Nato following the Iraq conflict, saying relationships were "fairly normal".

He stressed that Nato had helped support Poland and Spain's deployments in Iraq and he said he hoped Nato countries would take on a still greater role at some point.

Ahead of the Nato defence ministers' meeting, Mr Rumsfeld and his German counterpart, Peter Struck, held talks on the planned withdrawal of US forces from Germany.

Mr Struck said that "no doubt" remained that US forces would leave the country, but he said the process would take place over several years and with extensive consultations between the two countries.

The US is reviewing its overseas bases to improve its ability to deploy forces in the Middle East and Central Asia.