KIEV, April 21 – President Viktor Yanukovych on Wednesday agreed to extend stationing of Russia’s naval Black Sea Fleet in Sevastopol for at least 25 years to qualify for a 30% discount in natural gas prices.

The politically sensitive agreement, signed by Yanukovych and his Russian counterpart Dmitry Medvedev in Kharkiv, led to an outcry from opposition groups calling for the impeachment of the president.