Vladimir Putin and Slovak Prime Minister Robert Fico met at the Kremlin on Sunday in a rare face-to-face meeting to discuss the future of Russian gas deliveries.
The two leaders also discussed the conflict in Ukraine, just hours after Mr Putin warned of harsh reprisals against Ukraine for a drone attack on the city of Kazan, 1,000 kilometres from the Ukraine front line.
Slovakia is both a member of the European Union and the North Atlantic Treaty Organisation (NATO), a defence pact covering North America and many states in Western Europe.
The meeting was confirmed by Kremlin spokesperson Dmitri Peskov.
Mr Peskov did not give details of the talks but said it could be "presumed" that supplies of Russian gas would be discussed.
Ukraine announced this year that it would not renew a contract allowing the transit of Russian gas through its territory that runs out on December 31.
In a statement posted on Facebook after the talks, the Slovak leader said Sunday's meeting was "in response to" Ukrainian President Volodymyr Zelenskyy opposing any "transit of gas through Ukraine to our territory".
Mr Fico said Putin had confirmed Russia's "readiness… to continue to supply gas to the West and to Slovakia, which is practically impossible after 1 January 2025", but did not elaborate.
Both leaders exchanged views on the conflict in Ukraine, and "the possibility of an early peaceful end" to it.
Slovakia and Hungary, which rely on Russian gas, have raised concerns about the prospect of losing supplies.
Mr Fico last month announced he would travel to Moscow in May to attend a commemoration marking the 80th anniversary of the Second World War, accepting an invitation from Mr Putin.
But this visit was not announced.
When Mr Fico took office last year, Slovakia refused to continue military aid to Ukraine and began advocating for peace talks with Russia to end the conflict.
He is considered a nationalist and is one of the few European leaders to have remained close to the Kremlin in recent years.
Mr Fico's meeting comes a month after German chancellor Olaf Scholz called Mr Putin for the first time in almost two years, and urged him to find a "just and lasting peace".
Mr Scholz's call was condemned by Ukrainian president Volodymyr Zelenskyy, who feared it would undermine efforts to isolate the Russian leader.
Russian forces began a full-scale invasion of Ukraine in early 2022 and in recent months have been making steady territorial gains in the country's east.
AFP