"I received a promise from President Putin to support Syria politically, economically and militarily," Muallem said at a press conference with his Russian counterpart after meeting Putin.
Moscow has been a key backer of Syria's President Bashar al-Assad throughout the uprising against him that began in March 2011, providing diplomatic cover, as well as financial assistance to Damascus.
It has also hosted talks between regime figures and members of the tolerated domestic Syrian opposition, though they reached no firm conclusions and did not include the main internationally recognised opposition National Coalition.
"We are convinced that in the end the Syrian people will be victorious," he said.
"And our policy, which is intended to support Syria, Syria's leaders and its people, remains unchanged," he added.
Putin also raised the possibility of a new international coalition to fight "terrorism," especially the Islamic State group, which holds large swathes of territory in Syria and Iraq.
"If the Syrian leadership considers (forming such a coalition) acceptable and possible, we will do our best to support you," he said.
But Muallem appeared more sceptical about the prospect at the press conference with Russian Foreign Minister Sergei Lavrov.
"I listened with great interest to what President Putin had to say about the situation in Syria and the need to create a regional-international alliance to combat terrorism," he said.
"I know that Putin is a man who works miracles, but an alliance with Saudi Arabia, Turkey, Qatar and the United States would require a very big miracle," he said.
A coalition of countries led by Washington is already carrying out air strikes against IS in Syria and Iraq, but the United States has made clear it will not coordinate with Damascus in its fight against the jihadist group.
For its part, Damascus considers many of the members in the US-led coalition to be supporters of "terrorism" because of their backing for Syria's opposition.