“We are awaiting ... approval from the United States,” he said.
His words are quoted by TASS.
The Minister also expressed confidence that the three sides are ready and willing to meet.
Earlier, Riyad al-Maliki supported Russia's call for a Quartet ministerial meeting on the Middle East in the near future.
In August, Russia's Deputy Permanent Representative to the UN, Anna Evstigneeva, announced that the Russian side was proposing to hold a Quartet ministerial meeting on the Middle East at the UN General Assembly.
Later, Vladimir Safronkov, Special Representative of the Russian Foreign Ministry for the Middle East settlement, held talks with US Deputy Secretary of State Heidi Amr on issues of interaction between countries in Palestine and Israel.