Elements of the proposed policy, which officials cautioned have not yet been finalized, are being discussed by Secretary of State John F. Kerry in meetings this week and next with allies in Europe and the Middle East as part of a coordinated effort to end the bloody stalemate, which has claimed about 70,000 lives.
Those talks — along with a nearly two-hour meeting in Berlin on Tuesday with Russian Foreign Minister Sergei Lavrov and a Thursday conference with allies and leaders of the Syrian Opposition Coalition in Rome — are expected to weigh heavily on administration deliberations.
Kerry has repeatedly made indirect references to a policy shift during his travels. He told a group of German students Tuesday that the United States wants a “peaceful resolution” in Syria, but if its leaders refuse to negotiate and continue to kill citizens, “then you need to at least provide some kind of support” for those fighting for their rights.
On Monday in London, he said: “We are not coming to Rome simply to talk. We’re coming . . . to make decisions about next steps.”
Opposition political leaders had threatened to boycott the Rome meeting, but they were persuaded to attend after telephone calls in which Kerry and Vice President Biden said substantive proposals would be on the table.
The pending shift to a more active role comes as the administration and its partners backing the opposition, including Britain, France and countries in Syria’s region, have concluded that there is little immediate chance for a negotiated political settlement with Syrian President Bashar al-Assad.
Western officials have also acknowledged that the opposition coalition is unlikely to quickly develop a governing infrastructure or attract significant support from fence-sitting Syrian minorities and Assad supporters.
The opposition, meanwhile, has been strident in its criticism of the United States and others for refusing to provide it with the resources to organize a quasi-government and broaden its support inside Syria.
The Obama administration, citing legal restrictions on direct funding of the opposition, has funneled $385 million in humanitarian aid through international institutions and nongovernmental organizations, most of which operate under Syrian government supervision.
On the military side, the administration has established direct contact with rebel leaders but has limited aid to communications equipment delivered indirectly. A push last summer to arm the rebels, backed by then-Secretary of State Hillary Rodham Clinton, then-CIA Director David H. Petraeus and Defense Secretary Leon E. Panetta, was rejected by the White House in favor of continued efforts to build the political opposition.
While anti-government fighters have made significant gains against Assad’s military, concern has grown that militants linked to al-Qaeda have begun to dominate the opposition force. Early this year, Saudi Arabia and other Arab countries directly arming the opposition fighters increased weapons shipments to secular and moderate Islamist rebel factions after consultations with Washington.
A senior Arab official in the region said those armaments, including antitank weapons and recoilless rifles, have begun flowing into Syria. The New York Times reported Tuesday that at least some of those weapons were purchased in Croatia.
Britain and France have pushed to lift a European Union arms embargo on Syria. At a meeting in Brussels last week, political representatives of some of the E.U.’s 27 members refused to lift the year-long embargo entirely when it expires this Friday. Instead, they renewed it for three months and agreed to reconsider it in May.
More important, according to several European officials, the E.U. inserted a clause that allows member countries “to provide greater non-lethal support and technical assistance for the protection of civilians.”
Finalization of the new provision will be announced Thursday as Kerry and representatives of other governments meet with the opposition coalition in Rome, said officials close to the deliberations.
Although a number of countries opposed the change, it was favored by Britain, France, Germany and Italy, according to a European official, who like others spoke on the condition of anonymity to discuss rapidly evolving policies.
“Under the old E.U. setup, we couldn’t do anything,” a senior European official said. The new rule will allow “things that don’t of themselves kill people,” including night-vision equipment, armored vehicles and military training.
Another European official said, “We’re talking about things that can be helpful on the ground — bulletproof jackets, binoculars and communications.”
Each country participating in the effort is expected to decide for itself what equipment it will supply. The European officials said they have been in close contact with the Obama administration about its intentions and have been told that discussions are ongoing.
Asked Tuesday about prospects for expanding U.S. military support for the rebels, Kerry said he would not speculate on the outcome of the meeting with opposition leaders.
“We’re going to Rome to bring a group of nations together precisely to talk about this problem,” Kerry said. “I don’t want to get ahead of that meeting or ability to begin to think about exactly what will be a part of it.”
State Department spokeswoman Victoria Nuland said Kerry and Lavrov, his Russian counterpart, spent the bulk of their meeting discussing Syria. Lavrov met in Moscow on Monday with Syrian Foreign Minister Walid al-Moualem, who said the Assad government is willing to talk with opponents while continuing its fight “against terrorism.”
Opposition leader Mouaz al-Khatib deflected a Russian offer to visit Moscow amid disagreements within the coalition.
Lavrov called his meeting with Kerry “constructive” and told reporters that they agreed to do everything in their power “to create the best conditions to facilitate the soonest possible start of a dialogue between the government and the opposition,” Reuters reported.
He said Russia wants the opposition to name representatives for talks with the government, and he blamed “extremists” in the coalition for stopping progress toward negotiations.
Anne Gearan in Berlin and Scott Wilson contributed to this report.