That war could spill over into Lebanon and Iran as well as increase tension in Iraq and "there is such a threat," said Alexei Pushkov, head of the international affairs committee of the State Duma, the lower house of the Russian parliament.
He warned that the latest positive developments around Syria have not completely removed a threat of the U.S. military operation.
"The danger of a war remains and it is extremely high," Pushkov told a State Duma plenary session.
Russian President Vladimir Putin said Tuesday that placing Syrian chemical weapons under international control makes sense only if the United States drops its military strike plan against Syria.
Meanwhile, Vladimir Komoyedov, head of the State Duma Defense Committee, argued that U.S. President Barack Obama kept an attack on Damascus "in his pocket."
"Russian initiative to put Syrian chemical weapons under international control, in a sense, put President Obama into a deadlock. Apparently, Washington did not expect Damascus to accept Russia's proposals," Interfax quoted Komoyedov as saying.
He added that Washington had to backtrack on its preparations for a military operation against Syria under public pressure.
"Obama will keep an attack on Damascus 'in his pocket' despite the real opportunities that have presented themselves for a peaceful solution to the crisis in Syria," Komoyedov said.
On Tuesday, visiting Syrian Foreign Minister Walid al-Moualem said Damascus has accepted a Moscow proposal to put Syria's chemical weapons under international control to "stave off" a possible U.S. military strike.