BERLIN (Reuters) - The United Nations hopes to convene a new round of intra-Syrian peace talks in Geneva in August, the UN Special Envoy for Syria Staffan de Mistura said on Friday.

"We are determined to actually look for a proper date in August for relaunching the intra-Syrian talks in Geneva," de Mistura told reporters before a meeting with German Foreign Minister Frank-Walter Steinmeier.

The envoy said U.S. Secretary Of State John Kerry and Russian officials had agreed to take some "concrete steps" in addressing the situation in Syria, which could be helpful.

He said Turkish officials also assured him during a meeting in Ankara this week that they remained committed to working toward peace in Syria despite a failed coup attempt that has rocked Turkey.

"The next three weeks are going to be extremely important to give a chance for not only intra-Syrian talks, but also for some possibility of reducing violence," he said.

De Mistura said progress in U.S.-Russian talks on Syria would get the next round of intra-Syrian talks off to a good start and could help the warring parties take "credible, real steps in the direction of political transition."

He said the situation in Aleppo was critical, with about 300,000 people facing the threat of another siege.

Steinmeier also called for a return to political discussion among the warring parties in Syria. Without progress on the political front, a fragile ceasefire would be broken again and again, he said.

(Reporting by Andrea Shalal and Andreas Rinke)