Russian President Vladimir Putin said Ukraine's counteroffensive "has failed" as he hosted Belarusian leader Alexander Lukashenko for talks in St Petersburg on Sunday.

"There is no counteroffensive," Russian news agencies quoted Lukashenko as saying. Putin replied: "It exists, but it has failed."

Ukraine began its long-anticipated counter-offensive last month but has so far made only small gains.

Putin also mentioned on Sunday that the Ukrainian army has lost 26,000 troops since the start of the counteroffensive. Ukraine has not responded to the comment yet. 

The meeting between Russian and Belarusian leaders was the first since the latter helped broker a deal to end a brief mutiny by Wagner Group fighters last month.

During the meeting, Lukashenko told Putin that Belarus is keeping Wagner forces in central Belarus as he said in a jocular tone that Wagner fighters, who are now training Belarus's army, were keen to push across the border into NATO member Poland.

According to Russian media, Putin's talks with Lukashenko would last two days and another meeting is planned to be held on Monday.

(With input from agencies)