Serbia's President Aleksandar Vucic said on Sunday he wanted to avoid the "confiscation" of Russian shares in Serbian oil company NIS "at all costs," as his country looks for an exit from crippling U.S. sanctions.

Washington sanctioned Petroleum Industry of Serbia (NIS), which is majority-Russian-owned, as part of its crackdown on Russia's energy sector after Moscow's invasion of Ukraine in 2022.

The sanctions have hit hard in Serbia, which analysts say is on the brink of a winter energy crisis, with the country's lone oil refinery facing a potential shutdown.

Serbia had negotiated several postponements to the sanctions, but the U.S. Treasury Department began applying them on Oct. 9, and American authorities have now told Serbia that all Russian shareholders must exit the company for the sanctions to be lifted.

This creates a tricky situation for Serbia, a candidate for European Union membership and one of the few European countries not to have imposed sanctions on Russia over its invasion of Ukraine.

"I want us to avoid at all costs confiscation, nationalization or seizure of property ... We do not want to take anything from anyone," Vucic said during an emergency government meeting convened after Washington's latest announcement.

"I want us to exhaust all possibilities before committing to a takeover process or anything else," he said.

"We need to have a solution by next Sunday," he added, vowing the response would be "decisive."

NIS is 45% owned by Gazprom Neft, which has been targeted by U.S. sanctions. Its parent company, Gazprom, transferred its 11.3% stake in NIS in September to another Russian firm, Intelligence.

The Serbian state holds nearly 30% of NIS, with the rest owned by minority shareholders.

Vucic said negotiations between the Russian stakeholders and their "Asian and European partners" regarding a potential sale of NIS shares were ongoing, but did not name specific companies.

Since the imposition of sanctions, NIS has been unable to procure supplies. According to company representatives, its crude reserves will run out after Nov. 25.