President Donald Trump is defending his special envoy, Steve Witkoff, over the way he has conducted negotiations during the latest U.S. push to end the war in Ukraine and will send him back to Russia to meet again with Russian President Vladimir Putin.

Trump’s comments came Tuesday evening after Bloomberg published what it said was a transcript of a phone conversation on Oct. 14 between Witkoff and Yuri Ushakov, a top foreign policy aide to Putin. In the reported conversation, Witkoff appeared to offer the Russian official advice on how the Kremlin could win backing from Trump for its preferred terms to end the conflict.

Trump told reporters aboard Air Force One that Witkoff had been meeting with Russian and Ukrainian officials, and he cast the conversation as part of negotiations to end the conflict. Russia annexed Crimea in 2014 and then launched a full-scale invasion of Ukraine almost four years ago.

“I haven’t heard it, but it’s a standard thing,” Trump said of the conversation. “That’s what a deal maker does.”

Trump said that the latest flurry of U.S.-led diplomacy was making “good progress,” but that securing a deal was proving harder than he expected. The president said he thought his relationship with Putin would have made achieving a peace deal easier, and that reaching an agreement between the Russian and Ukrainian leaders was a “complicated process.”

The White House has said that the peace plan was developed by Jared Kushner, Trump’s son-in-law, and Witkoff, who met Russian officials several times before details of the plan emerged last week.

Trump last week set a deadline of Thursday for Ukraine to approve a U.S.-backed plan in his latest push to end the conflict, but he has suggested that the timeline is flexible if there are signs that the talks are making headway.

“We’ve settled eight wars,” claimed Trump, who is pursuing a Nobel Peace Prize and has repeatedly taken credit for ending a series of conflicts since taking office in January. “And I thought this would be one of the easier ones because of my relationship with President Putin. But this is probably one of the more difficult ones because there’s a lot of hatred.”

Trump did not say when Witkoff might return to Russia, but he said that Daniel P. Driscoll, the U.S. Army secretary, would meet with Ukrainian officials at the same time. Ukrainian President Volodymyr Zelenskyy’s chief of staff, Andriy Yermak, said on social media Wednesday that Driscoll was expected in Kyiv, Ukraine, later this week.

Russia’s state news agency, Tass, reported Wednesday that Witkoff would visit Moscow next week. Ushakov also told Russian state television Wednesday that he would speak to Witkoff about the purported leak of the phone call, calling it “unacceptable.”

The warmth of Trump’s relationship with Putin, cultivated during his first presidency and continued during his second term, has caused consternation to some political leaders in Washington and among many of the country’s allies, but Trump has argued that it gives him leverage in the Ukraine talks.