Ukrainian oligarch and Paul Manafort associate Dmytro Firtash is one step closer to seeing the inside of a U.S. courtroom.

The European Union Court of Justice issued a ruling on Wednesday denying the possibility for Firtash to appeal to the European Court of Human Rights.

The ruling removes a final hurdle to Firtash’s extradition to the United States, leaving it up to Austria’s Supreme Court to decide on the oligarch’s deportation.

Firtash’s attorneys wrote in a letter this month that the European court ruling would allow the oligarch’s case to be “quickly” decided.

“Mr. Firtash’s lawyers believe that the Austrian Supreme Court will move quickly and Mr. Firtash could face extradition in a short time frame following the decision by the Court of Justice,” wrote Firtash lawyer Dan Webb in an Oct. 9 letter to Chicago Federal Judge Rebecca Pallmeyer.

Firtash, a Ukrainian oligarch known alternately for acting as middleman in a scheme to jack up gas prices for European customers and for ordering Manafort to scout out an $850 million New York City real estate opportunity, has been awaiting extradition to federal court in Chicago since his arrest in Austria in March 2014.

Firtash, who prosecutors have alleged is “an upper-echelon” member of Russian organized crime, was indicted on foreign bribery charges relating to a scheme to gain rights to mine titanium in India for use in Boeing’s supply chain.

But after four years of litigation, Firtash has nearly exhausted his avenues to appeal the extradition request.

Manafort, who pleaded guilty to two conspiracy charges in September as part of special counsel Robert Mueller’s Russia probe, worked closely with Firtash and his associates while in Ukraine.

Apart from the alleged mission to scout out Manhattan hotel properties on Firtash’s behalf, Manafort was accused of collaborating with the oligarch on Ukrainian political campaigns in a New York lawsuit that was later struck down. Firtash denies the allegations against him.