President Vladimir Putin told Slovakian Prime Minister Robert Fico at a meeting in the Kremlin on Saturday that Russia will do everything to meet Slovakia's energy demand.
Slovakia is among only a few countries in Europe that are still buying Russia's oil and gas.
Slovakia gets Russian oil via the Soviet-built Druzhba pipeline, while natural gas from Russia flows there through the TurkStream pipeline.
Fico arrived in Moscow for the festivities to mark the Soviet Union's victory over Nazi Germany in World War Two.
"We will do everything to satisfy Slovakia's needs in energy resources," Putin told Fico, who chose not to attend the Victory Parade on Moscow's Red Square, in comments broadcast on national TV.
Russian state media had previously reported that Fico was due to attend the parade.
Slovakia, an EU member, has sought to maintain political ties with Russia and has argued that it would be too costly to wean itself off Russian supplies after building its infrastructure around them.
