Turkish Foreign Minister Feridun Sinirlioglu, U.S. Secretary of State John F. Kerry and Saudi Arabian Foreign Minister Adel al-Jubeir pose for a photo upon arrivaing for a meeting to discuss the Syrian conflict in Vienna. (Carlo Allegri/AFP/Getty Images)

A meeting of nations invested in the Syrian civil war will convene as early as next week to see whether they can chart a path to negotiations on the country’s future, Secretary of State John F. Kerry said Friday.

Speaking at the end of a day of meetings with diplomats from Russia, Saudi Arabia and Turkey, Kerry told reporters that they hope to meet next Friday to discuss ways to bring 4 1/2 years of fighting to a close. The meeting would include countries that are involved militarily, such as Russia and the United States, and countries that are swamped with Syrian refugees, such as Turkey and several European countries.

Kerry did not rule out the possibility that Iran, which along with Russia is the primary backer of Syrian President Bashar al-Assad, might someday participate in ­negotiations, but he declined to say when that might be.

“This is terrible human toll unfolding before our eyes,” he said, citing streams of refugees fleeing Syria and cities bombed to rubble. “It requires a global effort of all people of conscience, and nations, to do everything possible to bring this to a close.”

Kerry acknowledged that there is a basic difference of opinion on Assad’s future, with Russia and Syria saying he must stay until a military campaign destroys Islamic State militants and the United States and most other countries insisting that he step down.

But Kerry said all the governments concerned about Syria’s grinding civil war agree that the fighting must stop.

“All parties are agreed, now’s the time to end the fighting and advance this political transition,” he said. “The obvious question is, how do you get there? The answer is in discussions and consultations we are going to have.”

The multinational composition of the upcoming meeting reflects how the Syrian conflict has increasingly become a struggle involving dozens of nations.

Russia is the key country supporting Assad. In recent weeks, Moscow has positioned components of its military in Syria and conducted heavy airstrikes that have allowed Assad’s forces to resume ground offensives. The Russian military intervention has alarmed the Pentagon, which is leading a separate air campaign against the Islamic State.

Russia claims its attacks are primarily aimed at the Islamic State, but many of the Russian airstrikes have targeted other rebel groups fighting to oust Assad, who is also backed by Tehran.

Russian Foreign Minister Sergei Lavrov told reporters that Moscow wants more countries involved, in particular Iran and Egypt. “We requested that future contacts take place in a more representative format,” Lavrov told reporters after meeting with Kerry and the foreign ministers of Turkey and Saudi Arabia.

Rossiya-24 TV quoted Lavrov as saying that the Russian and Jordanian militaries have agreed to ­coordinate their activities in Syria. The United States and Russia also have agreed to communicate their whereabouts in Syria to avoid accidents between warplanes operating in the theater.

Earlier this week, Russian Presi­dent Vladimir Putin met with Assad in Moscow — the ­Syrian leader’s first known trip abroad since the war began more than four years ago. The visit suggested that Russia’s support for Assad is unwavering, but there may be an opening for negotiations that pave the way for an end to the conflict and a united front against Islamic State militants who have declared a caliphate in parts of Syria and Iraq.

On Thursday, Putin said he thinks that Assad is ready to have a dialogue with his political opponents. At a 2012 conference, diplomats drew up principles for a peace deal that included a transitional government to ease Assad from power. But that effort faltered, and a key opposition group recently threatened to boycott future talks.

Putin said Russia’s bombing campaign “will not solve all problems, but it will create conditions for the main thing: a beginning of a political process to encompass all healthy, patriotic forces of the Syrian society.”

The United States, while clear in its goals, has been unable to find an effective strategy to oust the militants or unseat Assad. In the meantime, Moscow has asserted itself, both militarily and diplomatically. After meeting Assad, Putin spoke by phone with the leaders of Turkey, Saudi Arabia, Jordan and Egypt.

The United States remains adamant that Assad has no future in Syria.

On Thursday, Kerry said that the countries with a vested interest in resolving Syria’s civil war share the “unified principles” that Syria should not be broken up, that it must remain secular, and that Syrians should choose their future leader. Then he reiterated that Assad must go.

“One thing stands in the way of being able to rapidly move to implement that, and it’s a person called Assad, Bashar Assad,” he told reporters.

“So the issue is can we get to a political process during which time the future devolution and allocation of power in Syria is properly allocated by the people of Syria? And that’s what we’re working towards,” Kerry said. “So my hope is that these talks can begin a process that could open up a greater discussion.”

Kerry also met with diplomats from Russia, the United Nations and the European Union to discuss ways to calm tensions and end a wave of violence in Israel and the West Bank. He talked with Israeli Prime Minister Benjamin Netanyahu on Thursday and plans to go to Amman, Jordan’s capital, for a meeting Saturday with Palestinian Authority President Mahmoud Abbas and Jordan’s King Abdullah.