By Yesim Dikmen and Daren Butler

ISTANBUL (Reuters) -Russian and Ukrainian negotiators began the first direct peace talks in more than two weeks on Tuesday in Istanbul, with the surprise attendance of Russian billionaire Roman Abramovich who is sanctioned by the West over Moscow’s invasion of Ukraine.

The two teams sat facing each other at a long table in the presidential office, with the Russian oligarch sitting in the front row of observers wearing a blue suit, a Turkish presidential video feed showed.

Three sources confirmed the unexpected attendance of Abramovich, who had already visited the country since the war began and has two of his superyachts docked at Turkish resorts.

In a speech ahead of the talks on the Bosphorus strait, Turkish President Tayyip Erdogan told the delegations the time had come for concrete results and that progress would pave the way for a meeting of the countries’ two leaders.

“It is up to the sides to stop this tragedy. Achieving a ceasefire and peace as soon as possible is to the benefit of everyone. We think we have now entered a period where concrete results are needed from talks,” he said.

“The negotiating process, which you have been carrying out under the orders of your leaders, has raised hopes for peace.”

Ukrainian television said the meeting began with “a cold welcome” and no handshake between the delegations.

Ukraine said on Monday its most ambitious goal at the meeting was to agree a ceasefire, while a senior U.S. official said Russian President Vladimir Putin did not appear ready to make compromises to end the war.

NATO member Turkey shares a maritime border with Ukraine and Russia in the Black Sea, has good ties with both and has offered to mediate the conflict. While calling Moscow’s invasion unacceptable, Ankara has also opposed the Western sanctions.

Russian forces invaded Ukraine on Feb. 24. Putin called it a “special military operation” to demilitarize Ukraine. Ukraine and the West say Putin launched an unprovoked war of aggression.

SUPERYACHTS IN TURKEY

The Kremlin has said Abramovich played an early role in peace talks but that the process was now up to negotiating teams. Sitting next to Erdogan’s spokesman at the talks, Abramovich adjusted his headphones to listen to the president’s speech, TV showed.

According to the Wall Street Journal and the investigative outlet Bellingcat, which cited people familiar with the matter, Abramovich and Ukrainian peace negotiators suffered symptoms of suspected poisoning earlier this month after a meeting in Kyiv.

Ukrainian officials poured cold water on the report.

The West has imposed heavy sanctions on Abramovich and other Russian billionaires, as well as Russian companies and Russian officials, in a bid to force Putin to withdraw from Ukraine.

Abramovich had sought to sell his English soccer club Chelsea, a process that was taken out of his hands by the British government when it blacklisted him.

The superyachts linked to him, together worth an estimated $1.2 billion, have been docked at Bodrum and Marmaris in southwest Turkey since last week. Sources have said he and other wealthy Russians were looking to invest in Turkey given sanctions elsewhere.

While calling Russia’s invasion unprovoked, Turkey has said it opposes sanctions imposed by its NATO allies on principle.

Its potential as a safe haven for Russian investment raises risks for Turkey’s government, banks and businesses that could face tough decisions and penalties if the United States and others ramp up pressure on Moscow with broader “secondary” sanctions.

(Additional reporting by Tuvan Gumrukcu and Orhan Coskun in Ankara;Editing by Jonathan Spicer and Frank Jack Daniel)