NATO tried to patch over divisions about the war in Afghanistan on Thursday but differences remained over the willingness of some members to contribute troops to the fight.
At a meeting in the Lithuanian capital Vilnius, defence ministers with troops fighting fierce battles against the Taliban in the south of Afghanistan backed calls by the United States for more countries to send forces there.
France said it was studying possible reinforcements and diplomats said Romania, Poland and Norway were among those who signalled they could do more. But, as widely expected, there was no formal offer of troops at the talks.
On a visit to frontline troops in the birthplace of the Taliban, U.S. Secretary of State Condoleezza Rice and British Foreign Secretary David Miliband also kept up the pressure on reluctant allies to share the combat burden.
Violence has risen sharply in the past two years in Afghanistan. Analysts say the country, which under the Taliban's hardline Islamist rule harboured al Qaeda before the Sept. 11 attacks, risks becoming a "failed state" again.
NATO Secretary-General Jaap de Hoop Scheffer said the 43,000-strong ISAF peace force in Afghanistan had made progress but acknowledged more needed to be done.
"I am cautiously optimistic," he said. "There are challenges, we need more forces ... the situation in Afghanistan means sharing responsibility and sharing risk."
U.S. Defence Secretary Robert Gates toned down his rhetoric, a day after saying NATO was at risk of splitting into members who are willing to "fight and die to protect people's security and those who were not".
But he stuck to his basic point that there was a contrast between nations such as the United States, Britain, Canada, the Netherlands and Denmark, doing most of the fighting in the south, and other NATO nations in safer parts of Afghanistan.
"I came away from the meeting encouraged," he said. "I think everybody understands the nature of the problem."
