An international conference made some progress on the way of banning cluster munitions.
But the meeting was marred by disagreements over how to define the deadly devices and how broad to make a ban, as well as by the absence of key producers and stockpilers - the United States, Russia, China and Israel.
Heinrich Haupt, head of the Conventional Arms Control division at Germany's Foreign Office, said it was "very regrettable" that the U.S., Russia and China did not attend the conference.
"We think that they should be on board ... this effort is worth it because it's an important cause that we're pursuing," Haupt said.
Cluster bombs, fired by artillery or dropped from aircraft, are canisters that open in flight and typically scatter hundreds of bomblets across a wide area. Some fail to explode immediately and can cause death or debilitating injury if disturbed - often years after a conflict has ended.
More than 135 countries attended the three-day gathering in Vienna. The conference was part of the so-called Oslo Process launched in February, when 46 countries laid plans for a treaty banning the use and stockpiling of cluster munitions that cause unacceptable harm to civilians by 2008.
Austria, one of the countries leading the effort, passed a law late Thursday banning all types of the weapons.
"There are still differences in opinion about the best way forward," Austrian Foreign Minister Ursula Plassnik said in a statement at the end of the meeting. She added, though, that a global alliance was taking shape.
Consensus appeared to emerge on humanitarian issues, such as helping victims, clearing areas and destroying stockpiles.
But some countries advocated continuing to allow cluster bombs with self-destruct mechanisms or low failure rates, according to members of the Cluster Munition Coalition, a network of groups seeking to protect civilians.
And some called also for a transition period during which cluster bombs could still be used, the group said.
Britain argued that cluster munitions had legitimate military purposes and that the removal of a type of weapon from their armory has to be given careful consideration so that their troops are not vulnerable in combat.
Germany suggested a compromise might be possible.
"When you summarize all our proposals, you reach a situation where the civilian population is protected and where some military needs are met," Haupt told The Associated Press.
John S. Duncan, Britain's ambassador for multilateral arms control and disarmament, said it was important to remember that the text of the declaration participants signed in Oslo referred to cluster munitions that cause unacceptable harm to civilians - not all types.
"Some members here now seem to be moving toward a total ban," Duncan said. But he said that was "not the general feeling of the meeting."
Simon Conway, co-chair of the Cluster Munition Coalition, said he was frustrated by the rhetoric of Germany, Britain and others but was confident they would change their minds.
"Ultimately, they will listen to logic," he said.
And he dismissed the argument that a treaty needed the support of the United States to be effective, suggesting the U.S. would adapt its behavior to take into account the concerns of other countries.
According to Belgium-based Handicap International, 98 percent of known victims of cluster bombs are civilians.
Last month, a U.N. weapons conference in Geneva called for new rules on when cluster bombs can be used but stopped short of launching talks on a legally binding treaty.
Proponents of the Oslo Process are scheduled to meet again in Wellington, New Zealand, in February and in Dublin, Ireland, in May, with the goal of negotiating a legally binding treaty by the end of next year.