Saying that “the military operation is really coming to an end,” Mr. Putin told Mr. Assad that it was time to work toward a lasting political settlement.
Parallel Russian- and American-led campaigns against the Islamic State have largely shattered the group’s territorial self-declared caliphate. But a solution to the underlying conflict — which began after Mr. Assad’s forces cracked down on political protests — remained elusive.
Insurgents unaffiliated with the Islamic State still hold patches of territory, besieged and bombarded by government forces, near the Syrian capital, Damascus; in the northern provinces of Aleppo and Idlib; and along the border with Jordan. Tens of thousands of people are missing, including civilians believed detained by the Syrian government. Twelve million Syrians, half the population, have been driven from their homes.
On Tuesday, the Syrian Network for Human Rights, which tracks war casualties through a database of victims identified by name, said that since March 2011, at least 26,446 children had been killed in the conflict, a vast majority by government forces.
“The main thing is to move to political processes,” Mr. Putin told Mr. Assad, according to Russian state news media. “I am pleased to see your readiness to work with everyone willing to establish peace and find solutions.”
Mr. Assad, who embraced the Russian leader and shook hands with a row of generals, replied, “We must admit that the operation made it possible to advance the process of political settlement in Syria.”
The United States and other international opponents have largely backed off their longstanding demand that Mr. Assad step down and have signaled willingness to accept a political transition that left him in power for at least some amount of time. But that remains unacceptable to many rebels and political opposition groups, and Mr. Assad has been accused in European courts of presiding over large-scale war crimes.
Riad Hijab, the leader of the opposition negotiating group that has been attending the long-stalled talks sponsored by the United Nations in Geneva, announced his resignation along with seven other members of the committee, a sign that they were under pressure to compromise more than they were willing to.
Russian state news media outlets said the Kremlin supported efforts by Saudi Arabia, which hosts the opposition committee, to reorganize the opposition, presumably an effort to recruit a committee that would agree to new parameters. A new Geneva round is scheduled to begin next Tuesday.
Mr. Putin then plans to host what he calls a Syrian Peoples’ Congress in Sochi on Dec 2. Initial plans for the meeting called for inviting 33 Syrian opposition groups, some tolerated by Damascus, as well as Kurdish groups, a much broader range than those included in the Geneva process. The meeting was postponed once over Turkey’s objections to inviting Kurdish groups that it sees as allied with Kurdish separatists in Turkey.
Another problem that remains unresolved is the fate of areas taken from the Islamic State by a Kurdish-led, American-backed militia called the Syrian Democratic Forces. The Syrian government has said it will fight to take the territory.
But the biggest problem, Neil Hauer, an analyst specializing in Russia’s involvement in Syria, wrote Monday, is “the opposition’s deep mistrust for Russia as a serious broker for an inter-Syrian settlement.”
Russia has already carved out a parallel process to Geneva, talks in Astana, Kazakhstan it has led with Iran and Turkey, which, Mr. Hauer wrote, has largely functioned as an effort by those countries “to impose their own policies on Syria regardless of the whims of local actors.”
But some Syrian rebels have taken part in the talks, saying they see little option. The main result of the Astana talks has been the creation of four so-called de-escalation zones, which were meant to calm violence but where in practice heavy bombardment continues, hitting trapped civilians as well as armed groups.
Also on Tuesday, President Hassan Rouhani of Iran declared “the end” of the Islamic State and congratulated the peoples of Syria, Iraq and Lebanon as well as “dear brother” Qassem Soleimani, the commander of the Islamic Revolution Guard’s elite Quds Force, who played a major role in battles in Iraq and Syria.
His remarks echoed those made on Monday by Hassan Nasrallah, the leader of Hezbollah, the Iran-backed Shiite militia group. Mr. Nasrallah spoke in more detail than he has previously done about Hezbollah’s involvement in Iraq, saying the group had sent many commanders to Iraq to aid in the ground battle against Islamic State.
Hezbollah has played an even larger and more prominent role in Syria. The new power, influence and weapons it gained in the process have roiled the region, as Saudi Arabia takes increasingly assertive steps to push back.
Mr. Nasrallah said that if his fighters would leave Iraq if they no longer needed.
But as the United States has learned repeatedly, declaring mission accomplished in Iraq does not mean the fight is over.