BEIRUT — The U.S. and Turkish governments on Sunday discussed sending non-lethal aid to the Syrian opposition, a move that could represent an incremental change in U.S. policy but comes as Syrian authorities seem to be regaining control of the country.

After a meeting on the sidelines of a summit in South Korea, President Obama and Prime Minister Recep Tayyip Erdogan of Turkey told reporters that they agreed on the importance of preventing more bloodshed in Syria, where for more than a year the government of President Bashar al-Assad has battled an uprising. The two leaders considered channeling medical and communications equipment to the opposition, according to a U.S. spokesman.

Turkey is preparing to host an April 1 Friends of Syria meeting that would include opposition groups, along with senior officials from nations supportive of them.

“We cannot remain a spectator,” said Erdogan, pointing out that 17,000 refugees had already poured into Turkey, which borders Syria.

The discussion represented a subtle shift in tone for the U.S. government, said Andrew Tabler of the Washington Institute for Near East Policy. Previously, although Obama has declared Assad an illegitimate ruler for his brutal crushing of the uprising, any discussion of helping the opposition has involved engagement with the largely expatriate political opposition groups.

A plan to send equipment to the ragtag rebels on the ground could signal a new willingness to recognize their legitimacy. However, the discussions come as the momentum in the Syrian struggle seems to be swinging back toward Assad’s forces, said Shadi Hamid of the Brookings Institution’s office in Doha, Qatar.

“Three weeks or a month ago, when the opposition seemed to have some momentum, this might have made sense,” he said. “But now the regime has had a series of tactical victories. This seems like tinkering around the margins.”

On Sunday, activists reported heavy shelling in the central city of Homs and, near Damascus, clashes between security forces and the armed opposition group known as the Free Syrian Army. Sixty people died, said the Local Coordination Committees activist group. The reports could not be independently verified, because Syria limits journalists’ access.

Human Rights Watch alleged Sunday that Syrian security forces have recently made civilians march in front of soldiers and pro-Assad militias as “human shields.”

Refugees from the northern province of Idlib, where activists say the army has been crushing the opposition using heavy artillery, told the New York-based watchdog group that they had been used as shields to protect the army from attack.

Diplomatic efforts to bring an end to the bloodshed continued Sunday, with a visit to Moscow by the U.N. and Arab League’s special envoy to Syria, Kofi Annan, who met with Russian President Dmitry Medvedev.

Russian leaders have condemned the West for calling for Assad’s departure, and they have urged the opposition to negotiate with the Syrian leader.

Medvedev told Annan: “This may be the last chance for Syria to avoid a long-lasting and bloody civil war. Therefore, we will offer you our full support at any level,” the Reuters news agency reported.

But most opposition figures remain implacable in their refusal to talk to Assad.

“He has to step down, pull his troops and militias from the occupied cities, towns and villages, release political prisoners, allow peaceful demonstrations,” said Ausama Monajed, spokesman for the prominent Syrian National Council opposition group. “Then we can negotiate with his deputy. There’s no meaning for negotiations without that.”