MOSCOW, September 7 (RIA Novosti) - Russian President Dmitry Medvedev instructed the head of the country's energy giant Gazprom on Monday to stick to the current gas contract with Ukraine regarding transit rates.

Alexei Miller said Kiev has repeatedly proposed altering the gas contract signed in January, under which Gazprom currently pays $1.7 per 1,000 cubic meters per 100 km for Russian gas transits across Ukraine.

"Don't pay then!" Medvedev said, urging action in line with the current agreement, referring to the deal on deliveries to, and gas transit through, Ukraine for 2009 agreed by the two countries' premiers in January.

Russia, which supplies around one quarter of Europe's gas, briefly shut down supplies via Ukraine's pipeline system at the start of the year during a dispute over Kiev's debt.

The Gazprom CEO said Russian gas transits had been paid in advance up to the second quarter of 2010.

Miller also reported that Ukraine had paid in full for Russian gas supplies over the past two months.

Ukrainian acting Finance Minister Ihor Umanskiy said last Thursday the ex-Soviet state's energy giant Naftogaz had paid Gazprom $667 million for August gas.

"The fact that our Ukrainian partners are paying is... a sign that our partners are duly honoring their commitments," the Russian businessman said.

Ukrainian Prime Minister Yulia Tymoshenko said late last month that Kiev was planning to buy around 25 billion cubic meters in 2010, half the agreed amount of gas stipulated in the 2009-2019 contract.