Transit of Russian gas through Ukraine will amount to about 70 billion cubic meters (bcm) in 2016, Ukrtransgaz chief Ihor Prokopiv said at a press conference in Kyiv on Thursday.

"As of today we are expecting 70 bcm," he said, adding that transit volumes declined substantially in recent days.

"We live by technical applications. Over the course of the year, there may have been applications for about 200 million cubic meters (mcm) per day on average, but now they have fallen steeply without explanation by the Russian side, to 130-140 mcm. This is cause for concern. As of today [July 28], transit rose to 150 mcm," Prokopiv said.

The likely cause of the decline in daily transit volumes is either a technical situation arising in Russia or oversupply of the European market.

"The Russians technically justify this as maintenance on their networks. A second possible cause is an oversupply on the European gas market. I don't think the Russians are failing to fulfill consumer orders deliberately. They did that in 2014-2015 and had to pay big fines," he said.