British Petroleum is one of the world’s largest oil and gas companies, so when it announced in February that it would sell its 19.75% stake in Russian energy company Rosneft in the wake of Vladimir Putin’s invasion of Ukraine, it held weight.

But nine months later, BP has yet to offload its stake, and one of Ukraine President Volodymyr Zelensky’s closest advisers is demanding the company cut ties immediately.

Oleg Ustenko, Zelensky’s chief economic adviser, penned a letter—viewed by BBC and the Guardian—to BP CEO Bernard Looney urging the company to make good on its pledge from the war’s early days, while accusing BP of being complicit with Russia’s international law-breaking and transgressions in Ukraine by holding on to its stake in Rosneft.

“After nine months of Russian aggression, war crimes, and the bombardment of civilian infrastructure, all funded and fueled by Russian oil, gas, and coal, BP remains a shareholder in Rosneft,” Ustenko wrote. 

A BP spokesperson told Fortune that the difficulties in selling BP’s stake in Rosneft stemmed from complications related to Western sanctions on Russian companies.

Ustenko also accused BP of continuing to receive payments from Rosneft in the form of dividends, citing a recent analysis by nongovernmental organization Global Witness. The analysis claimed that, by failing to sell its stake in Rosneft, BP “continues to receive profit distributions to shareholders, known as dividends,” from the Russian company. 

Based on a payout to Rosneft shareholders last month, Global Witness estimated that BP had pocketed around £580 million (about $713 million) in the first nine months of 2022.

The BP spokesperson said the company has not received any dividends from Rosneft shares since February, and did not expect to receive any in future, adding that the decision to sell its Rosneft shares led to a $24 billion hit.

They added that any payments a Russian company made to “unfriendly states” abroad would be strictly controlled by the Russian government. 

But Ustenko claimed in his letter that BP’s inability to sell its stake still makes it complicit in Rosneft’s massive profits this year, which have supported Russia’s war effort in Ukraine.

“BP will receive this money into a restricted Russian bank account, a clear indication of the historic mistake your company has made—but all the same, BP will receive the dividend,” Ustenko wrote.

“No accounting mechanisms or statements from BP will change this fact. This is blood money, pure and simple.”

Ustenko accused BP of “waiting out the storm, returning to business as usual when the war is over.”

The BP spokesperson denied this accusation, saying the company has “absolutely no intention of returning to ‘business as usual.’”

Throughout the war, Russia has resorted to using energy as a weapon against the West, especially Europe, which was dependent on Russia for the majority of its oil and natural gas supplies. Despite sanctions, Russia has managed to continue selling energy abroad this year, profiting wildly off of extremely high oil and gas prices during the first few months of the war.

Russian fossil fuel exports earned Russian energy companies 158 billion euros ($166 billion) during the first six months of the war, according to a study by the Centre for Research on Energy and Clean Air. Energy revenues contributed approximately 43 billion euros ($45 billion) to Russia’s federal budget since the start of the war, the study found, helping finance the war in Ukraine.