U.S. Co-Chairman of the OSCE Minsk Group, James Warlick

YEREVAN (RFE/RL)—James Warlick, a U.S. diplomat who has been Washington’s chief negotiator in the Nagorno-Karabakh peace process for the last three years, said on Monday that he will resign next month to work for a Russian law firm.

“I will step down as OSCE [Minsk Group] Co-Chair on December 31,” he announced on his Twitter page. “It has been an honor to serve in the [U.S. State Department] for more than 30 years.”

“I will be a Partner in Russia’s largest and most prestigious law firm,” Warlick said in a separate tweet. He posted a link to a statement issued by the firm, Egorov Puginsky Afanasiev & Partners (EPAM).

The statement said Warlick, who holds a master’s degree in law and diplomacy, will join the company’s Washington office in January. “He will be responsible for working with U.S. and international clients, development of strategic client relationships, legislation and public policy,” it said.

EPAM described Warlick as “one of the most respected senior U.S. diplomats” who “has worked extensively with Russia, Ukraine, Belarus and other CIS countries” and will offer “unique policy expertise and hands-on knowledge to clients who seek strategic advice and vision.”

The State Department did not immediately announce who will replace Warlick. His successor may be named by the incoming U.S. administration of President-elect Donald Trump.

Warlick, 60, was appointed as U.S. co-chair of the Minsk Group in September 2013. Together with the group’s two other, Russian and French, co-chairs he has since mediated many rounds of Armenian-Azerbaijani peace talks and visited the Karabakh conflict zone on numerous occasions. He previously served as U.S. ambassador to Bulgaria.

Warlick, Russia’s Igor Popov and France’s Pierre Andrieu are scheduled to hold talks with the Armenian and Azerbaijani foreign ministers in Germany on December 8 or 9. They may also arrange a face-to-face meeting there of the two ministers in a fresh attempt to kick-start the stalled peace process.