The White House said their discussion was "very productive" and that more details would be released later.
Meanwhile, the Ukrainian president described the meeting as potentially historic after the pair discussed the future of Ukraine.
After their conversation, Zelensky took to X and hailed it a “good meeting” with Mr Trump, adding: “We discussed a lot one on one.
Hoping for results on everything we covered. “Protecting lives of our people. Full and unconditional ceasefire. Reliable and lasting peace that will prevent another war from breaking out.
“Very symbolic meeting that has potential to become historic, if we achieve joint results,” the President added.
Sir Keir Starmer also met with Zelensky on Saturday afternoon in Rome, where the pair was photographed shaking hands alongside Trump and France’s Emmanuel Macron.
A Downing Street spokesperson said the pair discussed “positive progress made in recent days to secure a just and lasting peace in Ukraine.”
They agreed to “maintain momentum and continue working intensively with international partners to drive forward the next stages of planning”, the official added.