By Guy Faulconbridge and Vladimir Soldatkin ST PETERSBURG, Russia (Reuters) -Russian President Vladimir Putin quipped on Friday that in his view the whole of Ukraine was "ours" and cautioned that advancing Russian forces could take the Ukrainian city of Sumy as part of a bid to carve out a buffer zone along the border.

Russian President Vladimir Putin has revived a controversial narrative, claiming that theoretically "all of Ukraine is ours." He also sparked more immediate concerns with comments about seizing Ukraine's city of Sumy.

President Vladimir Putin said he isn’t seeking Ukraine’s “capitulation” as a way to end the war, even as he reiterated his claim that the two countries are one people.