WASHINGTON — The Senate has not yet scheduled a vote and is therefore unlikely to green-light the Trump administration’s choice of a retired Army lieutenant general to be the next U.S. ambassador to Ukraine, according to Senate and other sources.

A failure to vote would leave the naming of someone for a posting that has been vacant for around 18 months to President-elect Joe Biden’s administration.

Career foreign service officer Marie Yovanovitch was dismissed as the U.S. ambassador to Kyiv in 2019 and later testified to Congress claiming she had been the target of a campaign to discredit her by surrogates of President Donald Trump.

The White House announced on May 1 that it had nominated Keith Dayton, who currently serves as the senior U.S. defense adviser to Ukraine and as director of the George C. Marshall European Center for Security Studies in Germany, as Washington’s next ambassador to Kyiv.

Nominees for ambassadorships must be confirmed by a Senate vote.

Dayton and Julie Fisher, a career civil servant who was nominated to become the next U.S. ambassador to Belarus, had their Senate confirmation hearings in early August. The Senate approved Fisher’s nomination on December 15.

But there are currently no plans to vote on Dayton’s appointment before the current congressional session ends later this month, a spokesperson for one senator told RFE/RL.

“While Dayton wasn’t particularly controversial, there is no point in confirming him this late in the term when Biden will want the opportunity to nominate his own ambassador to Ukraine,” a spokesperson for another senator said.

A former U.S. career foreign service officer who is still active with Ukraine also predicted Dayton’s nomination would not move forward before Biden’s inauguration on January 20.

Biden has extensive Ukraine experience, having served as the point man to Kyiv when he was vice president during Barack Obama’s 2009-17 presidency.

Biden made six trips to Ukraine during his eight years in the White House.

Though Dayton served four decades in the Army, he is considered a political appointee as he is not a career foreign service officer. Political appointees frequently step down from their ambassadorial posts when a new administration enters the White House.

Analysts initially expected the 71-year old Dayton to be approved because he possessed significant experience in the former Soviet region, having served as U.S. defense attache in the U.S. Embassy in Moscow before being appointed in 2018 as senior U.S. defense adviser to Ukraine.

The United States has been without an ambassador to Ukraine since May 2019, when the Trump administration recalled Yovanovitch shortly before alleged efforts to pressure officials in Kyiv into investigating Biden and his son that were at the center of Trump’s impeachment, which concluded with an acquittal by the Senate in February.

Former Ukrainian Ambassador Bill Taylor served six months as charge d’affaires while the Trump administration sought a replacement until returning to the United States early this year.