Ukraine's President Volodymyr Zelenskiy holds a press conference during a NATO leaders summit in Vilnius, Lithuania July 12, 2023. (Photo: REUTERS)

Andriy Yermak, writing on the Telegram messaging app, also said officials from a number of countries were preparing to meet in Saudi Arabia to discuss Zelenskiy's peace plan for Ukraine, based on the departure of all Russian troops.

The talks on security guarantees with the United States are a follow-up on pledges issued by the Group of 7 at the NATO summit in Lithuania earlier this month to draw up and honour security guarantees.