Brazil’s President Luiz Inácio Lula da Silva said Wednesday he would try to urge Russian President Vladimir Putin to attend possible peace talks this week with Ukraine’s Volodymyr Zelenskyy, amid suspense over whether Putin would take part in the proposed meeting in Turkey.

Putin proposed restarting direct talks “without preconditions” on Thursday in Istanbul about the more than three-year war. Zelenskyy then challenged the Kremlin leader to meet in Turkey in person.

Lula has maintained close ties with Putin despite Russia’s invasion of Ukraine — a position that has caused tensions with the Kyiv government and raised eyebrows in the West.

Lula on Wednesday stopped over in Moscow on his return from a state visit in China, where he told journalists: “When I get to Moscow, I’m going to try to talk to Putin. It won’t cost me anything to say, ‘Hey, comrade Putin, go to Istanbul and negotiate.”

They did not meet, but the Kremlin said he and Putin spoke by phone. The Kremlin said Lula referenced the peace talks and “intends to do everything in his power to ensure their success.” It said Putin expressed gratitude for efforts to find ways to resolve the conflict.

The Kremlin did not mention any discussions of Putin’s possible travel to Istanbul.

Lula’s communications department said the Brazilian leader encouraged Putin to attend the talks, acknowledging, however, that it’s the Russian leader’s prerogative to select the delegation for the meeting.

The Kremlin on Wednesday said Putin’s aide Vladimir Medinsky will head the Russian delegation, which will also include Deputy Defense Minister Alexander Fomin, Deputy Foreign Minister Mikhail Galuzin and Igor Kostyukov, chief of the General Staff’s main directorate.

Medinsky led the Russian delegation at peace talks that took place in Belarus and Turkey in the first weeks of the war in 2022.