The Russian military has launched a video campaign to lure more professional soldiers to fight in Ukraine which challenges those interested to show they are "a real man" and swap what it casts as hum-drum civilian life for the battlefield.

The ad, set to stirring music, follows a report from British military intelligence and Russian media reports that suggest Moscow is seeking to recruit up to 400,000 professional soldiers - on a volunteer basis - to bolster its forces in Ukraine.

The ad has so far been released on major Russian social networking sites.

Russia, which says it is prosecuting what it calls "a special military operation," does not disclose full casualty figures. But up to 43,000 Russians have been killed in the war so far, according to a recently leaked estimate from the U.S. Defence Intelligence Agency.

It estimated up to 17,500 Ukrainians had been killed too.

The ad, which invites men to sign a contract with the Russian Defence Ministry for a salary starting at 204,000 roubles ($2,495) a month, shows a man in supermarket dressed in military uniform holding a heavy machine gun. He is then shown in the uniform of a security guard with the question:

"Is this the kind of defender you dreamt of becoming?"

Next in the video, a man is walking through the fog with other soldiers on what looks like a battlefield. He is then shown as a gym instructor helping a client lift weights.

"Is this really where your strength lies?" the video asks, before cutting to a taxi driver taking a client's fare who then transforms into a soldier on the battlefield.

"You're a real man. Be one," says the ad.

After launching a partial mobilisation drive in September which prompted tens of thousands of Russian men to flee the country to avoid being drafted, the authorities are playing down the possibility of a second mobilisation call - despite a move to introduce electronic call up papers to clamp down on draft dodgers - and are seeking to recruit volunteers instead.

Posters seeking professional soldiers have sprung up in the Russian capital in recent weeks declaring that "Our Profession is to defend the Motherland."

The posters, which say the army is looking for gunners, sappers, military medics, drivers and tank commanders, promise potential recruits "respect, an honourable profession and decent pay." ($1 = 81.7500 roubles) (Reporting by Andrew Osborn Editing by Guy Faulconbridge and Raissa Kasolowsky)