The former US ambassador to Ukraine – a central figure in the impeachment proceedings against US President Donald Trump – has retired from the foreign service, US media report.

Marie Yovanovitch was recalled last May after being accused of being disloyal to Trump. She denies the claims.

She gave evidence at the hearings which led to Trump’s current trial in the Senate over his Ukraine policy.

The president is likely to be acquitted by loyal senators on Wednesday, reports BBC.

The two charges that led to his impeachment by the lower House of Representatives are abuse of power and obstruction of Congress.

The first charge relates to an accusation that Trump withheld US military aid to pressure Ukraine into investigating a Democratic political rival, Joe Biden.