President Trump announced his nominee to serve as ambassador to Ukraine after the Senate’s impeachment trial thrust the relationship between Washington and Kyiv into the spotlight.

The White House said in a press release Friday that Trump is tapping Keith Dayton, the current director of the George C. Marshall Center in Garmisch, Germany, and the senior U.S. defense adviser to Ukraine. 

Dayton also served in the U.S. Army for 40 years, including stints as security coordinator for Israel and the Palestinian Authority, and the director of strategy, plans and policy at the Pentagon.

The U.S. has not had an ambassador in Ukraine since Marie Yovanovitch was recalled from her post in May 2019. 

The U.S.’s relationship with Ukraine has been the focus of intense scrutiny after Trump’s dealings with Kyiv sparked impeachment proceedings in Congress.

Democrats slammed Trump after a whistleblower and a subsequent reconstructed transcript of a call between Trump and Ukrainian President Volodymyr Zelensky showed Trump pressured Ukraine to investigate his political rivals. Witnesses later testified in front of Congress that Trump withheld millions of dollars in military aid to Kyiv to try to force it to conduct the requested probes.

Among the details revealed during Congress’s impeachment investigation was a conspiracy by Trump associates, including former New York City Mayor Rudy Giuliani, to try to get Yovanovitch removed from her post, believing that her anti-corruption stance would hinder their efforts to get Zelensky to authorize the investigations Trump wanted. 

The Senate ultimately acquitted Trump on charges of abuse of power and obstruction of Congress, and the president has repeatedly cast the proceedings as a “witch hunt.”