Russia has asked Kazakhstan to stand ready to supply it with 100,000 tons of gasoline in case of shortages exacerbated by Ukrainian drone attacks and outages, three industry sources told Reuters.

One of the sources said a deal on using reserves for Russia has already been agreed.

Shyngys Ilyasov, an advisor to Kazakhstan's energy minister, said the energy ministry has not received such a request from its Russian counterpart.

Russian energy ministry did not reply to a request for comment.

Neighbouring Belarus has already agreed to help Russia with gasoline supply.

Drone attacks had knocked out some 14% of Russian primary oil refining capacity as of end-March. So far authorities have said the situation on domestic fuel markets is stable and stockpiles large enough.

Russia is usually a net exporter of fuel and a supplier to international markets but the refinery disruptions have forced its oil companies to import.

The sources said Moscow asked Kazakhstan to set up an emergency reserve of 100,000 metric tons of gasoline ready to supply to Russia.

Moscow imposed a gasoline export ban for six months from March 1 to prevent acute fuel shortages, although it does not apply to the Moscow-led Eurasian economic union, including Kazakhstan, as well as some countries, such as Mongolia, with which it has inter-government deals on fuel supplies.

However, traders said the ban could be widened if the situation in Russia worsens.

Last week, the Orsk oil refinery in the Urals halted production due to widespread floods, which also affected Kazakhstan.

Kazakhstan, the world's largest land-locked country, has also restricted fuel exports until the end of the year, apart from for humanitarian purposes.

According to the sources, Kazakhstan's reserves of Ai-92 gasoline stood at 307,700 tons as of April 5 and Ai-95 gasoline stockpiles at 58,000 tons. Diesel reserves were 435,300 tons and jet fuel inventories totalled 101,000 tons.