The European Union nations remain divided on whether to ease sanctions against Syria to allow for weapons shipments to rebels fighting the regime of President Bashar al-Assad.
Britain is the most outspoken proponent of relaxing the arms embargo but faces opposition from some members that feel more weapons would only increase the killings and tarnish the EU's reputation as a peace broker.
German Foreign Minister Guido Westerwelle said it was not clear if the EU foreign ministers, meeting in Brussels, would reach an agreement on the issue.
"The positions are far apart," he said on Monday.
Assad has been using extensive firepower against lightly armed rebel factions.
More than 94,000 people have died since the uprising against Assad's regime erupted in March 2011, according to the latest UN figures.
Both sides have agreed in principle to enter direct talks in the Swiss city of Geneva next month, backed by both the US and Russia.
Several nations say that arming the opposition would create a level playing field that would force Assad into a negotiated settlement.
“It is important to show we are prepared to amend our arms embargo so that the Assad regime gets a clear signal that it has to negotiate seriously,'' William Hague, UK foreign secretary, said.
The date, agenda and list of participants for the so-called Geneva 2 conference remain unclear, and wide gaps persist about its objectives.
The opposition Syrian National Coalition, which has been meeting in the Turkish city of Istanbul since Thursday, has yet to reach an official position on the peace initiative.
Austria was among the holdouts to keep the EU from providing weapons, arguing it would only further fuel an already horrific situation.
"'We just received the Nobel Peace Prize and to now go in the direction of intentionally getting involved in a conflict with weapon deliveries, I think that is wrong," Michael Spindelegger, Austria's foreign minister, said.
Any decision would require unanimity among the 27 member states, but failing to come up with a decision would leave options for individual member states open.
"If there is no compromise, then there is no sanctions regime," Spindelegger said. "In my view that would be fatal, also for those who now absolutely want to deliver weapons."
Beyond the moral question of providing arms in a civil war, there are also fears that delivering weapons to the opposition would open the way for groups considered to be extremist to get hold of weapons that could then be targeted against the EU.
Over the past two years, the EU has steadily increased the restrictive measures against the Assad regime, including visa restrictions and economic sanctions.
In February, it also amended a full arms embargo to allow for non-lethal equipment and medicine to protect the civilians in the conflict.
If not renewed, all those measures expire at the end of the month.