By Ned Parker

UNITED NATIONS (Reuters) - The next round of United Nations-based peace talks on Syria have been scheduled for Feb. 20, diplomats told reporters on Tuesday.

The talks had been planned to begin in Geneva on Feb. 8 but Russia’s Foreign Minister Sergei Lavrov said last week that they had been postponed.

The UN envoy for Syria, Staffan de Mistura, said on Tuesday that he had decided to delay the UN-sponsored talks in order to take advantage of last week's negotiations between the Syrian government and opposition in Astana, Kazakhstan, hosted by Moscow, Ankara and Tehran.

The Astana talks ended with Moscow, Ankara and Tehran agreeing to monitor Syrian government and opposition compliance with a Dec. 30 truce.

"We want to give a chance to this Astana initiative to actually implement itself," de Mistura told reporters outside the Security Council. "If the ceasefire becomes as solid as we hope, that will only help the serious talk to achieve the concrete."

He added invitations for the UN-sponsored talks in Geneva would go out on Feb. 8. If the Syrian opposition cannot agree on its delegates, de Mistura said the UN would choose the opposition's representatives "in order to make sure that it can be as inclusive as possible."

De Mistura said the United Nations would be attending a follow up technical meeting on Feb. 6 of the Russia, Iran and Turkey backed talks in Astana on the implementation and monitoring of the Syria ceasefire.

(Reporting by Ned Parker; Editing by Lisa Shumaker)