Slovakia could take retaliatory measures against Ukraine after Kyiv halted the flow of Russian gas through its territory, Slovak Prime Minister Robert Fico warned Thursday.

The United Nations Refugee Agency said there were just over 130,000 Ukrainian refugees in Slovakia as of December 8.

Slovakia has alternative gas supplies but Fico, who has ended military aid to Ukraine and sought warmer relations with Moscow, says Slovakia will lose its own transit revenues and pay additional transit fees to bring in non-Russian gas. He has also said European gas and power prices would rise as a result of Ukraine's actions.