Syrian President Bashar al-Assad made a surprise trip to Moscow for a meeting with Russian leader Vladimir Putin.

The Kremlin made the announcement on Tuesday morning and published a photo of the meeting that took place between the two presidents on Monday evening.

According to the Kremlin, the talks focused on the conflict in Syria and Putin repeated his criticism of the presence of foreign troops in the country who were not there at the invitation of Damascus.

These troops are in parts of the country without a UN resolution and without "your (al-Assad's) consent," Putin was quoted as saying, describing it as a violation of international law.

Putin said the troops were hindering Syria's reconstruction and preventing a political settlement.

Russia, which conducts military operations in Syria, has been a close ally of al-Assad's government, propping it up through nearly a decade of war.

Turkey and the United States are among the nations that have intervened militarily on the side of al-Assad's opponents.

Putin last visited the Syrian president in Syria in early 2020.

Putin spoke of "joint efforts" that have yielded results. He referred, for example, to Russia's humanitarian aid and the delivery of Russia's Sputnik V coronavirus vaccine.

Al-Assad said he was happy to meet with Putin six years after the Syrian and Russian armies began working together “to liberate lands, bring back refugees to their cities and also protect innocent civilians” from terrorism.

Syrian rebel groups that have fought to remove al-Assad from power are referred to by Damascus as terrorists.

“We insist in Syria as a government and state institutions to go in parallel into the liberation of land and the political process,” al-Assad said, according to the Syrian presidency.

Al-Assad also thanked Russia for its support within international forums as well as humanitarian support.

dpa