NATO Secretary General Mark Rutte joined the talks with US special envoy Steve Witkoff, Jared Kushner - Trump's son-in-law - and US Senator Lindsey Graham, Zelenskiy said.
Ukraine plans to raise the possibility of an Easter ceasefire, the Ukrainian president told reporters on Tuesday, and will ask negotiators to pass the offer on to the Russian side.
In a Telegram post, Zelenskiy said he also spoke with UK Prime Minister Keir Starmer on Wednesday and briefed him on his ceasefire proposal.
"I informed Keir about the situation on the frontline: our positions are now much stronger," Zelenskiy said.
Ukraine has recently stepped up strikes on Russian oil infrastructure.
Roughly 40 per cent of Russia's oil export capacity has been halted, according to a Reuters calculation last week.
Zelenskiy has said Ukraine was ready to suspend such strikes if Russia agrees to stop attacks on Ukraine's energy infrastructure.
On Wednesday, the Russian foreign ministry rejected the ceasefire idea, calling it a "PR stunt".
The Kremlin reiterated that Ukraine should have withdrawn troops from the Donbas area - which Russia has failed to fully occupy during four years of war - "yesterday".
Ukraine sees ceasing hostilities at the current lines of fighting as a compromise and rejects Russia's demands to pull back from the land it still controls in the Donetsk region, part of Donbas.
Zelenskiy has repeatedly called for a summit with Trump and Russian President Vladimir Putin, saying the territorial issue could only be discussed at the leaders' level.
Following tense exchanges in recent days between US and European officials, Finnish President Alexander Stubb said on X on Wednesday that he spoke with Trump: "Constructive discussion and exchange of ideas on NATO, Ukraine and Iran".
