Russian strikes in recent days have wiped out more than half of Ukraine’s domestic natural gas production, likely forcing the war-battered country to spend 1.9 billion euros ($2.2 billion) on fuel imports to survive the looming winter.

Kyiv told its allies earlier this week that a massive Russian barrage targeting the Kharkiv and Poltava regions on Oct. 3 took out roughly 60% of the country’s gas production, according to people with knowledge of the matter. They requested anonymity because the discussions are private.