Secretary of State John F. Kerry, center, speaks with British Foreign Secretary Boris Johnson, left, and German Foreign Minister Frank-Walter Steinmeier before a meeting in Paris. (Pool photo by Thibault Camus /via European Pressphoto Agency)

Secretary of State John F. Kerry urged Russia on Saturday to “show a little grace” in allowing civilians and opposition fighters to safely evacuate their fast-shrinking eastern Aleppo enclave, even as U.S. officials scrambled to figure out which rebels want to leave and which may insist on staying to fight on in a battle now effectively lost.

“I believe there could be a way forward” to a larger political solution for Syria, Kerry said. “But it really depends significantly on big choices, magnanimous choices, choices of a genuine peaceful spirit that might come from Russia and, at the urging of Russia . . . from the Assad regime.”

Kerry’s comments, made alongside his counterparts from France, Germany and Qatar after a meeting here, were a tacit acknowledgment of the reality on the ground and a marked shift in tone from the angry accusations that have characterized recent U.S.-Russian exchanges on Syria.

In a later interview, Kerry indicated a broader shift in U.S. strategy for ending Syria’s civil war, saying that peace talks between the opposition and the government of President Bashar al-Assad could begin without a nationwide cease-fire.

“I think they could . . . and there are those of us who support that,” Kerry said. But to persuade opposition groups, and some of the other countries backing them, he said, “it’s going to be important to get some confidence-building structure into this equation. And that’s what we’re trying to do.”

Both a safe Aleppo evacuation and the start of talks on a political solution to the wider civil war require cooperation from Russia. U.S. and Russian military and diplomatic experts met Saturday in Geneva for talks that Kerry said were likely to continue. Their first task, he said at the news conference, was trying to “flesh out the details of a possible way to save lives” in Aleppo. But “I cannot stand here and tell you they will find a way forward.”

So far, he said, the fighters “don’t trust that if they indeed agree to leave . . . that it will in fact save Aleppo” or themselves. “That is the choice they see. To die in Aleppo or die in Idlib. But die” nonetheless.

Idlib is the neighboring province where the government has funneled civilians and opposition fighters who have evacuated other besieged communities.

The past year of meetings between Kerry and Russian Foreign Minister Sergei Lavrov, both by themselves and with other international stakeholders in Syria, has seen many failed plans for cease-fires and political negotiations. But despite the recent string of military victories for Russia-backed Assad, Kerry said he believes that success may provide an incentive for peace.

Moscow is well aware, he said, that the rebel defeat in Aleppo will not end the war. It may result in opposition fighters joining extremist groups, some of whose Russian and Central Asia members could launch terrorist attacks at home. At the same time, Kerry said, “this is very, very costly” for Russia.

“It costs them on their relationship with the Sunni countries in the region,” Kerry said. “It is not helpful to [President Vladimir] Putin’s economy, and it ain’t doing that much for their reputation.”

Widespread destruction in Syria will require massive reconstruction, and the West will refuse to help without a political settlement.

“If Russia’s going to own the thing,” Kerry said, “they want to own it with the least cost, least pain equation. And that’s not where it’s heading right now. It’s heading into a maximum-cost, maximum-pain equation. And I don’t think they want that.”

Kerry, who has been in near-constant communication with Lavrov this week, said that he “had two communications today that confirmed that [Assad] has said that he will, in fact, take part and be there in good faith and begin the negotiations . . . The Russians,” he added, “they really, basically, have put a hard guarantee down on that.”

But even if Russia and Assad did agree, it remains uncertain whether opposition political leaders — as well as countries backing the rebels such as Qatar, Saudi Arabia and Turkey — are now willing to sit down to negotiate their future. “They say they will go in without pre-conditions,” Kerry said of the political leaders. In the past, those pre-conditions have included a ceasefire, distribution of humanitarian aid and some assurances that Assad would not stay in power.

Their current position is “what we tried to pin down today,” Kerry said of the Saturday meeting here, which included Riad Hijab, the opposition’s chief political negotiator, as well as representatives from their European and regional supporters.

Meanwhile, Kerry said the situation in Aleppo was “confused,” as U.S. officials in contact with the rebels try “to really pin down which members of the armed opposition groups” have decided to leave the city.

A sporadic exodus of civilians continued out of eastern Aleppo on Saturday. Russia said Syrian troops had again suspended their offensive to allow 500 people needing urgent medical care to be evacuated. But reports from inside the city indicated ongoing government attacks and a delay in the evacuations because of security risks.

Louisa Loveluck in Beirut contributed to this report.