Russian President Vladimir Putin on Wednesday was hosting Syrian leader Bashar al-Assad for talks as the Kremlin seeks to mend ties between Damascus and Turkey's Recep Tayyip Erdogan.
The meeting follows the surprise announcement last week of a Chinese-brokered restoration of diplomatic ties between the Middle East's major rivals Saudi Arabia and Iran.
Ties between Erdogan and Assad were severed after the outbreak of fighting in Syria and successful Kremlin mediation would give Putin diplomatic clout with Russia isolated internationally over the Ukraine conflict.
"We are in constant contact and our relations are developing," the Russian leader told Assad at the televised start of their meeting, hailing "significant results in the fight against international terrorism".
Assad, who arrived in Moscow on Tuesday, voiced support for Moscow's military campaign in Ukraine and said the visit would mark "a new facet" in his country's ties with Moscow.
Kremlin spokesman Dmitry Peskov earlier told reporters the talks would focus on bilateral ties but said "Turkey-Syria relations will certainly be touched upon in one way or another".
Syria's civil war in 2011 strained relations between Damascus and Ankara, which has long supported rebel groups opposed to Assad.
Turkey severed diplomatic ties with Syria soon after the war began.
Analysts say Moscow now wants to bridge the divide between the two countries that see a common "enemy" in Kurdish groups in northern Syria, described as "terrorists" by Ankara and backed by Washington.
Erdogan has indicated he could meet with Assad, and their defence ministers met in Moscow in December, in the first such talks since the Syrian war began.
Diplomats from Russia, Turkey, Syria and Iran are due to meet in Moscow this week to pave the way for a foreign ministers' meeting, according to Turkish media.
Complex questions need to be resolved, however, particularly around the presence of Turkish troops in northern Syria.
Assad's government has been politically isolated since the start of the war, but he has been receiving calls and aid from Arab leaders after a February earthquake that killed tens of thousands in Turkey and Syria.
"The Syrian people faced another very serious problem, a catastrophe, an earthquake... As true friends, we are trying to support you," Putin said at the start of their meeting on Wednesday.
After the quake Putin offered Russian aid to Turkey and Syria.
Damascus is a staunch ally of Moscow, which intervened in the Syrian conflict in 2015, launching air strikes to support the government's struggling forces.
With Russian and Iranian support, Damascus won back much of the territory it lost in the early stages of the war.
The Syrian war has killed around half a million people and displaced millions more since 2011 with the brutal repression of anti-government protests.
Assad last visited Moscow in September 2021 when he also met Putin.