Vladimir Putin met Bashar al-Assad in Damascus on Tuesday, the Russian leader's second trip to Syria since Moscow intervened decisively on the Syrian president's behalf in the country's civil war.
The visit comes at a time of heightened regional tension - Assad's other main military ally, Iran, has said it will retaliate against the United States for the killing of an Iranian general in a drone strike.
Qassem Soleimani, who was one of the key figures in Syria's war as the architect of Iranian military operations in the Middle East, had just arrived in Iraq from Syria when he was killed by a US drone on Friday at Baghdad airport.
Russian and Iranian support has helped Assad win back nearly all the territory lost to Islamic insurgents who tried to overthrow him during the civil war that began nearly nine years ago.
Syrian state news agency SANA showed a photograph of Putin smiling as he shook Assad's hand and said they had listened to a military presentation by the head of Russian forces in Syria.
Putin and Assad discussed recent developments in the region and plans to "eliminate terrorism" in the Idlib region, one of the last pieces of Syrian territory held by anti-Assad insurgents, SANA reported.
Putin also delivered greetings to Russian forces in Syria.
Accompanied by Assad, Putin visited the Old City of Damascus including, the 8th century Umayyad mosque and an ancient church.
"I think Putin is there to reinforce the Russian position in Syria and with the person of Syrian President Bashar al-Assad, especially as Iran's position has been indelibly weakened, since Soleimani was essentially Iran in Syria," said David Lesch, an expert on Syria.
Though Iran and Russia worked together to beat back the anti-Assad insurgency, tensions have occasionally surfaced between them on the ground, where analysts say they have been vying for influence.
Putin is due to hold talks on Wednesday with President Tayyip Erdogan in Turkey, which has sent forces into much of northern Syria to beat back Kurdish-led forces that had been backed by the United States.
Putin's previous trip to Syria was in 2017, when he visited Russia's Hmeymim air base.
Putin told Assad that much had been done to restore Syrian statehood, while Assad thanked Putin for his assistance in restoring peaceful life in Syria, Russia's Interfax news agency reported, citing the Kremlin. Putin will visit several facilities in Syria during the trip, it added.
Soleimani, the Iranian general killed last week, had played a critical role in supervising Iran-backed ground forces to support the Syrian government during the war and coordinated with Moscow ahead of its intervention in 2015.