The economy minister of Slovakia, which relies on Russian natural gas for around 85% of its demand, said the country could not be cut off from Russian gas flows, and if it had to pay for it in Russian rubles, it would, although it backed taking a common European Union stance, Reuters reported.

"The [natural] gas [flow] must not stop," Slovak Economy Minister Richard Sulik said in a Sunday debate show on public broadcaster RTVS. "If there is a condition to pay in rubles, then we pay in rubles."

Sulik added Slovakia would continue to work on a common approach with the EU.

Slovakia said last week that state natural gas company SPP had paid its March invoice for natural gas in euros, as stipulated in its contract.

Sulik said the country still had six weeks to find a solution before the next natural gas payment is due May 20, but Slovakia could not go without deliveries.