The United States has backed Ukraine in a $173 million dispute with Russian oil producer Tatneft, which has appealed a four-year freeze on enforcement and accused Ukraine of using the war to keep the case on hold indefinitely.
The U.S. Department of Justice recently filed an amicus brief with the U.S. Court of Appeals for the District of Columbia Circuit that backs Ukraine’s effort to maintain restrictions on Tatneft’s enforcement of an arbitration award tied to its former stake in Ukraine’s Kremenchuk refinery.
Tatneft has appealed a stay on post-award discovery that has largely blocked its access to information about Ukrainian assets since Russia invaded Ukraine in February 2022. The company says the suspension has lasted more than four years with no clear date for full enforcement action. It accuses Ukraine of reliance on “unsupported assertions and innuendo” to keep the case on hold indefinitely.
In its Aug. 27 brief, the U.S. government said Ukraine presented credible evidence that Tatneft’s discovery efforts could expose sensitive military and economic information to Russia. It described Tatneft as a company with strong ties to the Russian government and said such disclosure could harm Ukrainian and U.S. national security interests.
“The Russian Federation has increasingly become a surveillance state with severely eroded rule-of-law protections,” the U.S. government said. It said sensitive information obtained by Tatneft could ultimately reach Russian authorities, even if the company sought to keep it confidential.
Washington asked the D.C. Circuit to dismiss Tatneft’s appeal or deny its request to restart discovery. The Justice Department said that if discovery resumes, the court should limit its scope to account for Ukraine’s security concerns and sovereign immunity protections.
Tatneft, meanwhile, continues to seek broader access to information about Ukrainian assets.
In a Sept. 8 filing in the Southern District of New York, Tatneft’s lawyers rejected Ukraine’s proposal to limit the next phase of discovery to 10 commercial banks selected by the company. They said those restrictions were unlikely to uncover assets that could satisfy the award.
“Tatneft gave consent-based discovery a try. It did not work,” the company’s lawyers said. They asked the court to lift the remaining restrictions and consider motions over access to information from financial institutions and other entities.
Tatneft argues that Ukraine should not be allowed to cite the war and national security concerns to block enforcement indefinitely. The award stems from a dispute that began years before Russia’s invasion.
The dispute began in 2007, when an armed raid at Ukrtatnafta, operator of the Kremenchuk refinery, removed the company’s elected management. Tatneft subsequently lost its stake in the venture and launched a legal battle to recover its assets. In 2008, it initiated international arbitration against Ukraine. Tatneft claimed the loss of its investment violated a bilateral investment protection agreement between Russia and Ukraine.
An international arbitration tribunal ruled in Tatneft’s favor in 2014 and awarded the Russian company $112 million in damages. Tatneft turned to U.S. courts to enforce the award in March 2017. Ukraine opposed the action, in part on sovereign immunity grounds. A U.S. federal court in 2019 confirmed the award with accumulated interest bringing the amount owed to approximately $173 million.
Ukraine continued to challenge enforcement. In December 2021, however, the D.C. Circuit upheld the arbitration award. Tatneft then sought information from financial institutions to identify Ukrainian assets that could satisfy the award. Its New York case included subpoenas to 25 financial entities for information about Ukraine’s accounts and activity in bond and securities markets.
Russia’s full-scale invasion in February 2022 interrupted those efforts. Tatneft and Ukraine jointly asked the courts to suspend discovery because of the war, and the courts stayed the proceedings. Tatneft later sought to restart enforcement arguing that a temporary measure had turned into an open-ended freeze.
Tatneft moved to lift the stay in Washington in June 2025. In March this year, the district court denied the request without prejudice, prompting the company to appeal to the D.C. Circuit.
The latest filings put two issues before the U.S. courts. Tatneft seeks to enforce an award confirmed before the current war, while Ukraine, backed by the U.S. government, argues that broad disclosure of its financial and state assets to a Russian company could create security risks while the conflict continues.
Tatarstan-based Tatneft is a major Russian base oil and lubricants marketer. Ukrtatnafta operates the Kremenchuk refinery, which has not returned to sustained crude processing since Russian missile strikes caused extensive damage in 2022. Parts of the site remain in use for petroleum storage and product handling and Russia has repeatedly targeted the facility, most recently in a reported Aug. 27 attack.