No formal offers have been made by Nato states in response to requests by commanders in Afghanistan for 2,500 extra troops, Nato says.
Nato has commanded the Isaf peacekeeping force since 2003
Members are meeting in Belgium amid pressure from the International Security Assistance Force, which is fighting in southern Afghanistan.
Differing rules of engagement between Nato states are creating difficulties.
However, a Nato spokesman said there were "positive indications" some might consider sending forces in the future.
There are at least 18,500 foreign, mainly Nato soldiers in Afghanistan in addition to about the same number of US troops deployed.
Half of them are in the south where Canadian and British forces are sharing the burden with US aircraft support and special forces on the ground.
In the latest violence, Afghan police say they killed 16 Taleban fighters in a fierce gun battle overnight in Helmand province.
The fighting came as US Secretary of State Condoleezza Rice warned that Afghanistan was at risk of becoming a "failed state".
All nations were represented at the meeting in Mons, near Brussels, and Nato's Supreme Command was to solicit offers for a reserve battalion of ground troops.
ISAF TROOPS IN AFGHANISTAN
Total Isaf troops - 18,500
Contributing nations - 37
Isaf - International Security Assistance Force
*A further 18,000 non-Isaf, US-led troops also in country
Alliance spokesman James Appathurai told a news briefing that "no formal offers were made at the table".
However, he said the extra troops were not needed to complete the continuing offensive in Afghanistan.
"Operation Medusa is going well and achieving its operational objective," Mr Appathurai added.
Correspondents say Nato will be hoping for a firm commitment by a meeting of alliance defence ministers in two weeks.
Nato officials also said there had been a positive signal that some members with troops in northern Afghanistan, under restricted rules of engagement, might be willing to operate more flexibly.
"The Canadians, Brits and many others are fighting very, very hard and they're stretched thin, and they need overall support," Mr Appathurai said.
The Dutch, Australians and Estonians are also in southern Afghanistan but correspondents say many other countries have been reluctant to commit troops to what is currently the most dangerous part of the mission.
Earlier, UK Prime Minister Tony Blair said it was of "fundamental importance" to security that the "the job in Afghanistan is done properly".
"We should never forget that the reason why our troops are in Afghanistan, along with other Nato countries, is because out of Afghanistan came the terrorism of 9/11," he said.
On Tuesday US Secretary of State Condoleezza Rice said Afghanistan's strategic position meant it risked becoming a haven for militant groups.
Referring to a US decision to leave the country after the withdrawal of the Soviet Union in 1989, Ms Rice said, "We all came to pay for that."
Speaking in Canada, she explained that the US should learn its lessons from Afghanistan.
"If you allow that kind of vacuum, if you allow a failed state in that strategic location, you're going to pay for it," she said.
Last month, Nato commanders took over from US-led coalition forces but there has been a resurgence of Taleban attacks, above all in the south.