ST. PETERSBURG, Russia, June 4 - Russia-U.S. talks on economic and energy issues continue despite a pause in Ukraine peace negotiations, President Vladimir Putin's special envoy Kirill Dmitriev told Reuters on Thursday, adding he spoke to U.S. counterparts a day earlier.

The Kremlin said on May 18 that the Russia-Ukraine peace process was on hold but that Moscow expected it to resume, with contacts between Moscow and Washington continuing at different levels.

"We talked to Steve Witkoff and Jared Kushner yesterday. So the dialogue continues, and there is constant communication," Dmitriev said on the sidelines of Russia's biggest economic conference, referring to U.S. negotiators.

TRILATERAL TALKS POSSIBLE WHEN 'TIME IS RIGHT'

U.S. President Donald Trump and Putin last spoke on April 29, discussing a temporary Ukraine ceasefire to mark the anniversary of the end of World War Two. Dmitriev last met with Kushner and Witkoff in April.

Since the brief ceasefire, military action has escalated. Russia has struck Kyiv and other Ukrainian cities with drones and missiles, while Ukraine has hit refineries, ports, and other industrial sites deep inside Russia.

The U.S.-mediated peace process, launched at Russia-U.S. talks in Riyadh in February last year, has stalled over a part of the Donbas region still controlled by Ukraine that Moscow wants handed over before agreeing to a settlement.

Dmitriev said not all Russia-U.S. contacts were tied to Ukraine and that both sides would continue discussions on energy, the economy, and global stability. He added trilateral talks with Ukraine were possible.

"And then when the time is right, I think there will be an opportunity also for trilateral discussions, but this is more on a diplomatic track," Dmitriev said.

The U.S. on May 18 extended for a third time a 30-day sanctions waiver allowing purchases of Russian seaborne oil to help "energy-vulnerable" countries affected by the Iran war.

Dmitriev, who was involved in talks with the Trump administration on previous extensions, said U.S. officials understood the waivers' role in stabilizing markets during the Middle East crisis.

"Extending waivers before was good for the markets. I think the U.S. administration understands that without Russian oil, without Russian gas, it's impossible to have stability in the energy markets," Dmitriev said, declining to say whether the waiver will be extended again this month.