Ukraine is planning to significantly increase reverse gas supplies through Hungary from May 21 under a contract that was signed on May 14, Naftogaz CEO Andriy Kobolev has said.

"Yesterday a contract was signed with a large European company, which will allow us to significantly increase reverse supplies from May 21 at a price that is acceptable for us," he said at a press conference in Kyiv on Thursday.

However, he declined to say with which company the contract had been signed, and on which terms, saying these were commercial secrets.