Iranian President Hassan Rouhani and his Russian counterpart Vladimir Putin held a conversation on the telephone on Saturday for the third time over the past month.
They exchanged views about the latest developments in Syria, particularly after the recent major defeat of terrorists and full liberation of the strategic city of Aleppo from the grips of foreign-backed militants.
The Iranian and Russian presidents also stressed the importance of developing cooperation to help the resumption of dialogue and negotiations to find a political solution to the crisis in Syria.
The Iranian and Russian chief executives had also held phone talks on December 19 and November 28.
The Syrian military announced on Thursday that it had attained full control of the northwestern city of Aleppo, having completely cleansed its eastern side of militants for the first time since 2012.
The victory came about despite military support for the militants by the United States, Turkey, and some Arab countries in the Persian Gulf region.
The Russian president on Friday called his Syrian counterpart Bashar al-Assad to congratulate him on the full liberation of Aleppo, saying, "This success was possible thanks to mutual efforts of all who came together in the fight with international terrorism in Syria."
Also in an annual conference on Friday, Putin said the evacuations in Aleppo would not have been possible without the help of his country, Iran, and Turkey and the goodwill of President Assad.
He urged a nationwide ceasefire deal and said the four sides had agreed to attend peace talks in the Kazakh capital, Astana, to try to resolve the conflict in Syria.
Russia has been carrying out an aerial campaign against militants in Syria, including formerly in Aleppo, on a request from the Syrian government. Iran, too, has been offering Damascus advisory military help.
Iranian Foreign Minister Mohammad Javad Zarif and his Russian and Turkish counterparts Sergei Lavrov and Mevlut Cavusoglu, respectively, held a meeting in Moscow on Tuesday and discussed the latest developments in Syria, particularly those concerning Aleppo.