The visit to Syria, a key ally of Iran, came amid soaring tensions in the Middle East between Iran and the United States.
On Friday, a U.S. drone strike killed a top Iranian general who led forces supporting Assad in Syria's civil war. Iran has vowed revenge for the slaying, and with some 600 American troops deployed in Syria, the country is a potential site of conflict with Iran.
While the official statements made no mention of the U.S. killing of Iran's Revolutionary Guard General Qassem Soleimani on Friday, the timing was conspicuous.
Soleimani had led Iran's armed support for Assad as armed rebels neared the capital, Damascus, and he helped seize key cities, preventing the collapse of Assad's state. Thousands of Iranian-backed fighters remain scattered across Syria.
Putin and Assad met Tuesday at a Russian command post in Damascus, and were presented with military reports on the situation in different regions of Syria, Kremlin spokesman Dmitry Peskov said.
In his conversation with Assad, Putin said "a huge distance has been covered in terms of restoring Syria's statehood and territorial integrity," Peskov said.
Russia joined the war in 2015. The Syrian government has largely won nearly 9-year-old civil war militarily, and has retaken control of most of the country from rebel fighters.
In recent weeks, Syrian troops supported by Russian warplanes have been pushing into the country's last rebel stronghold, located in the northwestern Idlib province.
Putin's visit Tuesday coincided with Russian Orthodox Christmas, and Putin congratulated his troops on the holiday, according to a statement from Assad's office. Photos released by SANA showed the two leaders visiting an orthodox cathedral in Damascus.
The last time Putin came to Syria was in 2017 when he announced a scale-back of the Russian military presence there. Assad previously visited Russia and met with Putin in May 2018, November 2017 and October 2015.
More than 400,000 people have been killed in Syria's civil war and 11 million have been displaced from their homes, including 5 million who are refugees outside the country.