KIEV, March 19 – Events in Crimea raise the potential threat to the revision of Kharkiv agreements of 2010 under which Russia's Gazprom gave a $100 discount per 1,000 cubic meters of gas to national Naftogaz Ukrayiny in exchange for prolongation of the stay of the Russian Black Sea Navy in Sevastopol, Ukrainian Energy and Coal Industry Minister Yuriy Prodan said.

"The discount of $100 was linked to the staying of Russian Navy on our territory. Now the circumstances have changed, there is a large question over whether the discount is possible in the future," he said in an interview with the Publichnye Liudi magazine.