Ukrainian President Volodymyr Zelenskyy said on Saturday that he had had a long and "substantive" phone call with U.S. President Donald Trump's special envoy Steve Witkoff and Trump's son-in-law Jared Kushner.

"Ukraine is determined to keep working in good faith with the American side to genuinely achieve peace. We agreed on the next steps and formats for talks with the United States," Zelenskyy said on X.

Witkoff and Kushner had held two days of talks with Ukraine's senior negotiator Rustem Umerov in Miami this week, which both sides called "constructive discussions on advancing a credible pathway toward a durable and just peace in Ukraine."

Witkoff had been expected to brief Umerov on his meeting in Moscow this week with Russian President Vladimir Putin.

Zelenskyy said he was waiting for Umerov to give him a detailed report in person in Kyiv.

"Not everything can be discussed over the phone, so we need to work closely with our teams on ideas and proposals," Zelenskyy said. "Our approach is that everything must be workable – every crucial measure for peace, security, and reconstruction,"