Moscow: The Kremlin said on Wednesday that a potential US-Russia deal to allow Syrian rebels to safely leave Aleppo was still on the agenda, but that no talks were planned between the two countries for now.

Kremlin spokesman Dmitry Peskov told reporters on a conference call that Russian and US experts were in contact about Syria, but said he was not aware of any talks being planned at a higher level.

“As regards the exit of rebels ... there was a proposal for an exit and the theme has been previously discussed, and this question is (still) on the agenda,” said Peskov.

“Unfortunately, very few have left so far and the majority are still there.” Peskov spoke as rebels in besieged eastern Aleppo called for an immediate five-day ceasefire, negotiations about the future of the city, and for medical and civilian evacuations.

Peskov said rebels in eastern Aleppo were rallying around former Al Nusra Front fighters.

“All these rebels are terrorists,” said Peskov.

Russian Foreign Minister Sergei Lavrov was due to meet US Secretary of State John Kerry in Hamburg later on Wednesday, the Russian Foreign Ministry said.

Russia also said that an army colonel working as a military adviser in Syria has died several days after being wounded by rebel shelling in Aleppo.

“Ruslan Galitsky passed away in hospital as a result of his serious injuries. Russian army medics fought for several days to save his life,” the defence ministry said in a statement carried by Russian news agencies.

It said he was wounded in the shelling of a residential area in western Aleppo by the “so-called opposition”.

Galitsky — who reportedly commanded a tank brigade based in Siberia — is one of the highest ranking Russian servicemen among the roughly 20 Moscow says have been killed in Syria.

The statement did not specify where or when exactly Galitsky died but said he had already been awarded a posthumous military award.