Russian representatives were not present at the talks, which opened in Florida on Saturday.
They were originally expected to attend the negotiations, which were due to take place in Abu Dhabi.
The US team was led by special envoy Steve Witkoff and Jared Kushner, President Donald Trump's son-in-law.
"It is clear that the US side's attention at the moment is focused primarily on the situation surrounding Iran and the wider region, but Russia's war against Ukraine must also be brought to an end," Zelenskiy said in an evening address.
"There are indications that further (prisoner of war) exchanges may take place, which would indeed be very good news and confirmation that diplomacy is working. We hope this will come to fruition."
Zelenskiy did not specify whether the talks would continue, when or where they might take place, or in what format.
Earlier on Sunday, he urged allies to keep up sanctions pressure on Russia and called for tougher action against Russia's so-called shadow fleet of tankers used to avoid sanctions, and for Moscow to be denied oil revenues.
"Russia's shadow fleet must not feel safe in European waters or anywhere else. Tankers that serve the war budget can and must be stopped and blocked, not just let go," he added.
Washington has temporarily lifted some sanctions on Russian oil to help cope with supply shortages caused by the war in Iran. European countries have not done so.
A peace plan being promoted by the US would require a presidential election in Ukraine, alongside territorial concessions.
Zelenskiy, whose term has already expired, is under renewed pressure from Trump to hold a vote as Washington pushes Kyiv towards a peace deal.
Ukrainian law bars wartime elections, but Zelenskiy has said Ukraine would be ready to hold democratic elections if the US secured a two-month ceasefire to allow time to prepare infrastructure and put security guarantees in place.
Ukraine's former top general, Valeriy Zaluzhnyi, now ambassador to Britain and seen as a potential presidential candidate, said Ukraine did not need a pause in fighting to vote.
"What Ukraine needs is not time to prepare for and hold elections, but a peace won through war, which will secure a future for our children," he wrote in an article published on Sunday by Ukrainian outlet NV.
