Kazakhstan expects to resolve the issue with coal supply to Ukraine in the summer period, the director of the Kazakhstan Association of Mining and Metallurgical Enterprises Nikolai Radostovets said.

"Coal is always needed in the winter time. Those who buy coal try to pay and buy coal when it is needed-- in August, September and October, and so on until March. During this period, barriers had been created to impede Kazakh coal miners from delivering coal to Ukraine. It involves the Russian side in the first place," he told Interfax.

"Ukrainian consumers took a time out during a non-heating period to wait and see how the situation will be developing. We think it is very important to settle the issue of an uninterrupted coal delivery to Russia and Ukraine at the international level. Kazakhstan should keep its position of a major coal exporter," Radostovets said.

"During this summer, the government should obtain guarantees from the Russian government and Russian National Railways that coal would be transported continuously and empty cars returned back to Kazakhstan on time," he said.

Earlier Radostovets said that "it is a very sensitive issue, because Kazakh supplies have been limited due to the fact that Russia bars transit of Kazakh coal."

It was reported that an agreement on Kazakh coal supplies to Ukraine was reached in December 2014 during Kazakh President Nursultan Nazarbayev's visit to this country.