Ukrainian President Volodymyr Zelenskyy on Tuesday said his country needs to convince U.S. President Donald Trump that Vladimir Putin is not a trustworthy partner as he urged the Russian president to show up for peace negotiations in Turkey later this week.

“Trump needs to believe that Putin actually lies,” Zelenskyy told a group of reporters in Kyiv, according to The Guardian. “And we should do our part. Sensibly approach this issue, to show that it’s not us that is slowing down the process.”

Zelenskyy has called on Putin to join him for peace talks in Istanbul on Thursday. While the Russian president has yet to respond to the invitation, Kremlin spokesperson Dmitry Peskov said a Russian delegation would be traveling to the country for talks with Kyiv but said he would only be able to share the names of those attending once he received “an instruction to do so” from Putin, according to Reuters.

Zelenskyy has made clear he will be waiting for Putin, warning that his absence would send a clear message to all parties involved.

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

Zelenskyy has said he has no interest in meeting a Russian delegation that does not include Putin, explaining that Putin is the only one who can commit to a ceasefire.

While Trump is in the Middle East this week, he has floated the possibility of flying over to Turkey if he feels the two sides are close to reaching an agreement. Trump on Wednesday told reporters that Putin “would like me to be there.”

“I don’t know that he would be there if I’m not there,” he added.

Zelenskyy noted that a commitment from Trump to join him in Turkey would likely incentivize Putin to attend.

“It’s the situation where the U.S. being present can give important guarantees,” he added, according to The Guardian.

So far, Trump has only confirmed the attendance of U.S. Secretary of State Marco Rubio. Trump envoys Steve Witkoff and Keith Kellogg are also expected to make the trip, Reuters reported.

Earlier on Tuesday, Kellogg told Fox Business’ Maria Bartiromo that Trump will be in Turkey if Putin shows up.

“This could be an absolutely incredible meeting with them,” he said. “We can get peace, I really believe, pretty fast if all three leaders sit down and talk.”

Meanwhile, European Union High Representative Kaja Kallas predicted the Putin-Zelenskyy meeting wouldn’t go ahead.

“I don’t think [Putin] dares, I guess,” she added.