Kazakhstan’s Foreign Ministry says it is continuing with preparations for the third round of Syrian peace talks in Astana, despite reports that Syrian rebels are seeking a postponement.

"We haven't received any notification yet," a ministry spokesman said March 11. "We are still getting ready for the announced dates," March 14-15.

Delegates are expected from Russia and Iran, which back Syrian President Bashar al-Assad's government, and from Turkey, which supports some Sunni-Arab rebel factions.

However, on March 11, Syrian rebel groups called for the talks to be postponed.

They said future meetings should depend on whether Assad's government and its allies adhered to the most recent cease-fire, set to run March 7-20 and brokered by Russia and Turkey.

Two previous rounds of Astana talks ended without a breakthrough.

The Kazakh ministry said diplomats from the United Nations, the United States, and Jordan are also being invited to the talks.

The UN special envoy on Syria, Staffan de Mistura, says he has also asked the warring parties to return to Geneva later in March as efforts intensify to end Syria's six-year conflict, which has killed an estimated 300,000 people and displaced millions more.

The conflict has also involved fighters of the Islamic State (IS) militant group -- opposed by both sides -- which has complicated matters on the ground further.

With reporting by Reuters, TASS, and Interfax