( CNN ) -- Russia began to cut off natural gas supplies to Belarus on Monday as talks over unpaid debts continued , Russian state media reported . President Dmitry Medvedev gave the order for Russian energy giant Gazprom to start restricting gas supplies , company CEO Alexei Miller said , according to official Russian news agency RIA-Novosti . Miller said the cut , which began Monday , will be `` gradual , daily and proportional to the volume of debt . '' Belarus has refused to pay Russian gas rates of $ 169 per 1,000 cubic meters for the first quarter of the year and $ 185 for the second quarter , RIA-Novosti reported . The former Soviet republic has instead been paying $ 150 since Jan. 1 , ringing up a large debt in the process . Russia 's action could hurt customers farther down the pipeline . Belarus has said it will be technologically unable to ensure complete natural gas transit to Europe , if Russia cuts gas supplies to Belarus by 85 percent , state media reported . In the past , other countries including Austria , Bulgaria , the Czech Republic , Germany , Romania , Greece and Turkey have complained that their gas supplies have been affected as Russia trimmed output to upstream customers like Belarus and Ukraine . Gazprom is the world 's biggest producer and exporter of natural gas -- and Russia 's most powerful company . It controls 20 percent of the world 's natural gas reserves and operates the world 's largest gas distribution network covering an area from Europe to the Far East , according to its website . Gazprom exports energy to 32 countries and provides around 25 percent of the European Union 's gas supplies . Formed in 1989 to replace the Soviet Ministry of the Gas Industry , Gazprom is closely tied to the Russian government , which owns a controlling 50 percent stake in the company . Medvedev is a former Gazprom chairman . In recent years , an increasingly confident Moscow has used Gazprom to assert its authority over Russia 's former sphere of influence by offering heavily subsidized gas to ex-Soviet countries . But that policy has led to disputes as Gazprom has then sought to raise prices . Gazprom has switched off gas supplies to another former republic -- Ukraine -- several times in recent years in a row over payments and Kiev 's rejection of proposals to hike rates . Those disputes ended earlier this year when Russia agreed to a 30 percent drop in the price of natural gas sold to Ukraine , in exchange for permission to extend Russia 's lease of a major naval base in the Black Sea port of Sevastopol , Ukraine , for 25 years .
NEW : Belarus says it ca n't guarantee natural gas transit to Europe . Talks to continue over debts owed to Russia by Belarus . Gas cuts will be `` gradual '' Gazprom operates the world 's largest natural gas distribution network .