Russian President Vladimir Putin met with Iranian President Hassan Rouhani and Turkish President Recep Tayyip Erdogan in Sochi on Wednesday. The leaders discussed a diplomatic solution to the conflict in Syria as the war against the "Islamic State" (IS) and Syrian rebel groups winds down.

Following the talks, Putin announced the plans for a congress bringing together regime and opposition figures, due to be held in Sochi before UN-backed talks kick off next week in Geneva. 

Putin, Erdogan and Rouhani laid out plans for a peaceful settlement in Syria in a joint-statement after the meeting. The leaders stressed the need for all parties in the conflict to release all prisoners and hostages, hand over bodies and create the conditions for a lasting ceasefire.

Read more: Syria conflict: What do US, Russia, Turkey and Iran want? 

Putin said that with Syrian opposition forces weakened, the conditions were in place to end the civil conflict, after six-and-a-half years of fighting, although compromises on all sides would have to be made.  "It is obvious that the reform process will not be simple, it will require compromise and concessions from all parties, including obviously the Syrian government," Putin said following two hours of talks.

Russian support for Syrian President Bashar Assad has turned the tide in the six-year civil war in favor of the regime.

"We have reached a consensus on helping the transition to an inclusive, free, fair and transparent political process that will be carried out under the leadership and ownership of the Syrian people," Erdogan said.

Turkey had been one of the main backers of the Syrian opposition but has turned its attention on pushing back gains made by US-backed Kurdish forces, who control 25 percent of Syrian territory after combatting IS. It has now joined Russia and Iran in mediating a peace settlement.

Peace talks in Astana

Turkey, Iran and Russia are co-sponsors of peace talks in the Kazakh capital Astana, which bring together some parts of the political and armed Syrian opposition.

The talks have led to the establishment of four so-called de-confliction zones, including in Idlib

which is largely controlled by al-Qaida linked forces that are not party to negotiations. The de-escalation zones have reduced violence, but fighting still continues.

The Astana talks are designed to support the UN-backed talks, but critics say they are meant to allow Russia to steer a political solution in Syria without significant involvement of the United States. Putin's calls to host a future congress in Sochi will only further raise those suspicions. 

Russia and Iran celebrate defeat of IS

The tri-lateral meeting comes a day after Assad made a surprise visit to Sochi, for his first meeting with Putin since 2015 shortly after Russia intervened to bolster the regime in Damascus.  The same day in Sochi, the military chiefs of Iran, Turkey and Russia met to discuss coordinating military strategy.

Putin used the Assad visit to trumpet Russia's military success against both IS and foreign backed rebels, echoing a similar statement made by Iran's Rouhani saying that IS had been defeated.

"As for our joint work in the fight against terrorism in Syria, this military operation is coming to an end," Putin said in comments released Tuesday. "Thanks to the Russian army, Syria has been saved as a state. Much has been done to stabilise the situation in Syria," Putin said.

Read more:

- Syria conflict: What do US, Russia, Turkey and Iran want? 

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Seeking recognition

Joshua Landis, a Syrian expert and head of the Center for Middle East Studies at the University of Oklahoma, told DW that Putin wanted to send a message that Russia and Iran had largely defeated IS and foreign backed opposition forces. 

"There remains much for them to do in order to consolidate their success, but they are seeking recognition of their position in the hope that world opinion will accept their victory as an ineluctable fact and cease to oppose them by sponsoring opposition members, arming militants and imposing new sanctions," he said. 

Putin's spokesman Dmitry Peskov said that Putin had assured the leaders of Turkey and Iran that "Russia will work with the Syrian leadership to prepare the groundwork for the understandings that could be reached in Sochi on Wednesday and to make sure that agreements that could be reached would be viable."

It remains unclear what role Assad would play in a future Syria, which has been a major stumbling block in attempts to find a political solution. 

Russia and Iran have stated that the Syrian people must decide on their own leadership.

Russia leads diplomatic charge

Putin's diplomatic offensive also included calls with the US President Donald Trump and the leaders of Saudi Arabia, Egypt and Israel.

According to the Kremlin, Putin told Trump that "the Syrian leader confirmed his commitment to the political process, (and) conducting constitutional reform and presidential and parliamentary elections."

The White House said Putin and Trump stressed the importance of "supporting the UN-led Geneva Process to peacefully resolve the Syrian civil war, end the humanitarian crisis, allow displaced Syrians to return home, and ensure the stability of a unified Syria free of malign intervention and terrorist safe havens."

Israel is concerned that Iran and its Lebanese Shiite ally Hezbollah will set up permanent bases in southern Syria that could threaten Israel.

Saudi Arabia shares similar concerns with Israel over Iranian influence in Syria.

Syria opposition also meets 

The armed and political Syrian opposition met in Saudi Arabia on Wednesday in a bid to bridge differences ahead of the UN talks in Geneva on November 28.

They included the Turkey-based Syrian National Coalition, the Saudi-formed High Negotiations Committee and Cairo and Moscow-based groups.

Speaking at the openning of the three-day summit in Riyadh, UN Envoy for Syria Staffan de Mistura, said:  "It is our common interest that today, you elect the best and most inclusive team among yourselves. A strong, unified team is a creative partner in Geneva and we need that."

However, before the meeting, more than a dozen figures from High Negotiations Committee (HNC) and its head Riad Hijab, resigned in protest over what they said was pressure to accept that Syrian President Assad could remain in power.

The High Negotiations Committee had led the opposition in previous UN-backed talks with representatives of the Syrian government.

Infighting within the Syrian opposition and defeats on the battlefield have resulted in the Arab Gulf states, Turkey and the US urging various parties to drop some of their demands. 

cw,dm/rt (AFP, AP, dpa, Reuters)