WASHINGTON/ISTANBUL, May 15 (Reuters) - U.S. President Donald Trump and his Russian counterpart Vladimir Putin will not attend what could be the first direct peace talks between Moscow and Kyiv in three years on Thursday, the Kremlin sending instead a group of experienced technocrats.

Putin on Sunday proposed direct negotiations with Ukraine in Istanbul on Thursday "without any preconditions". Late on Wednesday, the Kremlin said the delegation would include presidential adviser Vladimir Medinsky and Deputy Defence Minister Alexander Fomin.

After the Kremlin's delegation announcement, a U.S. official said Trump would not attend - days after saying that he was considering the trip.

While Putin had never confirmed he would attend in person, the absence of the Russian and U.S. presidents lowers the expectations for a major breakthrough in the war that Russia started in February 2022.

Ukrainian President Volodymyr Zelenskiy had challenged the Kremlin leader to attend the talks "if he's not afraid," in an apparent contest to show Trump who wants peace more. Zelenskiy was on his way to Turkey, a Ukrainian official said. Earlier, the Kyiv leader has said he would take part in the negotiations only if Putin were there.

Trump wants the two sides to sign up to a 30-day ceasefire to pause Europe's biggest land war since World War Two, and a Russian lawmaker said on Wednesday there could also be discussions about a huge prisoner of war exchange.

Zelenskiy backs an immediate 30-day ceasefire, but Putin has said he first wants to start talks at which the details of such a ceasefire could be discussed.

Photo from Reuters