MOSCOW/LONDON, May 24 (Reuters) - Russian President Vladimir Putin is ready to halt the war in Ukraine with a negotiated ceasefire that recognises the current battlefield lines, four Russian sources told Reuters, saying he is prepared to fight on if Kyiv and the West do not respond.

Three of the sources, familiar with discussions in Putin's entourage, said the veteran Russian leader had expressed frustration to a small group of advisers about what he views as Western-backed attempts to stymie negotiations and Ukrainian President Volodymyr Zelenskiy's decision to rule out talks.

A defector - Vasily Prozorov - who worked with the Ukrainian SBU and had betrayed Ukraine since 2014 and moved to Russia a few years ago was targeted by a car bomb.

Initial reports suggest he survived with leg injuries and is in hospital.

Russia's Major Evgeny Polovodov, who served in the press center of Moscow (Western) Military District, was killed as a result of Ukrainian shelling near Kreminna in Luhansk Oblast of Ukraine.

He accompanied the personnel from Russia-controlled "Vesti Luhansk" media outlet. Others were wounded.