TALLINN, Estonia — The talks have taken place in the warring capitals of Moscow and Kyiv, from Washington and Riyadh, Saudi Arabia, to countries across Europe. Now, all eyes are finally turning to Istanbul to seek an end to Russia’s 3-year-old, full-scale invasion of Ukraine.

Russian President Vladimir Putin proposed restarting direct peace talks today with Ukraine in the Turkish city that straddles Asia and Europe. And President Volodymyr Zelenskyy challenged the Kremlin leader to meet in Turkey in person.

What will unfold remains unclear. The Kremlin said its delegation at the talks will be led by Putin’s aide, Vladimir Medinsky, and include three other officials. Ukrainian presidential adviser Mykhailo Podolyak said Zelenskyy will only sit down with the Russian leader.

Zelenskyy said Tuesday that “if Putin does not arrive and plays games, it is the final point that he does not want to end the war.”

How did the idea of talks in Turkey arise?: On Saturday, Zelenskyy hosted French President Emmanuel Macron, U.K. Prime Minister Keir Starmer, German Chancellor Friedrich Merz and Polish Prime Minister Donald Tusk in a show of unity. They issued a coordinated call for a 30-day ceasefire in Ukraine starting Monday.

The plan has received backing from the European Union and U.S. President Donald Trump, who had promised during his campaign to swiftly end the war that is now in its fourth year. The leaders pledged tougher sanctions on Russia if Putin did not accept the proposal.

Who’s coming and why?: The Kremlin on Wednesday night 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.

The Kremlin’s list did not include Putin himself.

Zelenskyy said Tuesday he will meet with Turkish President Recep Tayyip Erdogan in the capital Ankara, and wait there. If the Russian leader chooses Istanbul for the meeting, Zelenskyy said, then he and Erdogan will travel there.

If Putin doesn’t show, European and U.S. leaders should follow through with additional sanctions against Russia, he added.

What are both sides’ demands to end the war?: Putin last year demanded that Ukraine cede the four regions, which it still does not fully control. He also wants Kyiv to recognize the Crimean Peninsula, also illegally annexed by Moscow in 2014, as Russian; Ukraine also must renounce its bid to join NATO and drastically reduce its army. He also demanded that the West lift sanctions imposed on Moscow after the invasion.

Kyiv, in turn, refused to cede any land and wants robust security guarantees against future Russian aggression.

Several attempts to establish at least a partial ceasefire have been unsuccessful.