KYIV, Ukraine (AP) — Ukraine’s president says he has discussed a new contract for natural gas supplies from Russia during a conversation with Russian President Vladimir Putin.

Volodymyr Zelenskiy said he discussed the gas deal with Putin during Monday’s phone call. Zelenskiy said Tuesday that the deal is a priority for Ukraine and important for Europe’s energy security.

Talks on a replacing a contract expiring this year have dragged, raising fears of disruptions of Russian gas supplies to Europe via Ukraine.

Price and debt disputes led to disruptions of Russian gas deliveries to European customers during the winters of 2006 and 2009.

Relations between Russia and Ukraine have remained badly strained since Russia’s annexation of Crimea in 2014 and Moscow’s support for a separatist insurgency in eastern Ukraine.