He shared the information in an interview with Radio Liberty.
"Ukraine continues to transit Russian gas exclusively to support our European colleagues, European partners, certain EU countries, especially those so-called landlocked countries that have no access to the sea. And today they need this volume," Chernyshov explained.
He also noted that the EU plans to completely abandon Russian gas by 2027, but Ukraine seeks to "speed up and stimulate this process."
The Naftogaz CEO said that the transit agreement will expire at the end of 2024.
"As for this contract, we also have to be a reliable partner for our European partners, for the countries that need it. But this agreement will expire by the end of 2024, and we have no intention or initiative to extend it," he said.
Prime Minister Nikolay Denkov accused Hungary and Serbia of not looking for alternative sources of energy supplies, instead financing Russia's war in Ukraine.