BERLIN (REUTERS, AFP) - Kremlin critic Alexei Navalny has been removed from a medically induced coma and is responding to speech, Berlin's Charite hospital said in a statement on Monday (Sept 7).

The hospital, which has been treating Mr Navalny since he was airlifted to Germany for treatment after falling ill on a Russian domestic flight last month, said he is being weaned off mechanical ventilation.

"It remains too early to gauge the potential long-term effects of his severe poisoning," Charite said in a brief statement.

Mr Navalny, a prominent critic of President Vladimir Putin, was airlifted to Germany last month after collapsing on a flight from the Siberian city of Tomsk to Moscow. It made an emergency landing in Omsk so that Mr Navalny could be stretchered off.

German Chancellor Angela Merkel has said Berlin has concluded Mr Navalny, 44, was poisoned with Novichok, the same substance that Britain said was used against Russian double agent Sergei Skripal and his daughter Yulia in an attack in England in 2018.

Novichok is a military-grade poison that was developed by the Soviet government towards the end of the Cold War and can be deployed as an ultra-fine powder, liquid or vapour.

Moscow says it has seen no evidence Mr Navalny was poisoned.

The incident has put the future of Germany's Nord Stream 2 pipeline with Russia in doubt as a growing number of politicians call for support for the project to be withdrawn unless Russia helps to clear up the circumstances around Mr Navalny's poisioning.

Dr Merkel's spokesman said on Monday she does not rule out imposing sanctions on the pipeline in response to the suspected poisoning.