BERLIN (REUTERS) - Former German Chancellor Gerhard Schroeder met Russian President Vladimir Putin for several hours on Thursday evening in a bid to end the war in Ukraine, Germany's Bild am Sonntag (BamS) reported, although it was unclear what was achieved.

Citing a person with detailed insight into Schroeder's activities, the weekly newspaper said Schroeder had also had a long talk with one of Putin's closest advisers.

He left Moscow early on Saturday morning with his wife and flew to Istanbul, the paper said, without disclosing any further details of the conversations.

The former chancellor, who is a personal friend of Putin and has links to Russian companies, had met a group of Ukrainians with links to the country's delegation for peace talks with Russia in Turkey on Monday evening, reported BamS.

The source told BamS that Schroeder was currently the only person to have had direct contact with both Putin and top Ukrainian officials.

News website Politico first reported that Schroeder was flying to Moscow for talks with Putin, and German government sources said it had not agreed to any meeting nor been involved in one.

The government's press office referred to remarks made by Chancellor Olaf Scholz on Friday when he declined to comment on the meeting beyond saying that he would take note of any results and include them in other efforts he was involved in.

Scholz, who travels to Turkey on Monday, spoke to Putin in a three-way phone call with French President Emmanuel Macron on Saturday (March 12).

Schroeder, Social Democrat (SPD) chancellor from 1998 to 2005, is on the board of Russian oil giant Rosneft and is chairman of the shareholders' committee of the company in charge of building the Nord Stream 2 pipeline, which has been shelved.

He has faced calls from some German government politicians to step down from his roles over Russia's invasion of Ukraine.

Nobody was immediately available at Schroeder's office.