Trump spoke out in support of his personal lawyer after Giuliani confirmed his role in Yovanovitch's removal, calling him "a great crime fighter".
Taylor earned Trump's ire with testimony before House impeachment investigators when he recounted his experience in dealing with a parallel diplomatic channel with Ukraine.
"I forced her out because she's corrupt", Giuliani told Fox News on Monday.
In this handout photo provided by Adriii Derkach's press office, Rudy Giuliani, an attorney for U.S. President Donald Trump, left, meets with Ukrainian lawmaker Adriii Derkach in Kyiv, Ukraine, Thursday, Dec. 5, 2019.
The top USA diplomat in Ukraine, William Taylor, will be leaving his post next month, following a short term marked by the impeachment inquiry into President Donald Trump. Giuliani said he was not the first person to go to the president with concerns about the diplomat.
Giuliani's comments come as Trump faces near-certain impeachment on Wednesday by the House for abuse of power over his pressure on Ukraine to announce investigations of Democrats while he was withholding aid to the Eastern European nation. And during Robert Mueller's investigation of Trump & Co. last December, Giuliani was there talking about the case and the sentence of Michael Flynn.
According to the broadcaster, Taylor's departure from Kiev was expected because he was one of the key witnesses that could shed light on the circumstances of the telephone conversation trump and Ukrainian leader Vladimir Zelensky, affecting including the investigation of former Vice-President of the United States Joseph Biden and his son hunter.
Both Taylor and Yovanovitch gave testimony to the House during its impeachment inquiry. She was OBSTRUCTING JUSTICE and that's not the only thing she was doing.
He claimed Ms Yovanovitch "committed perjury" when she said she turned down the visa requests for a prosecutor because he was corrupt.
Former US ambassador to Ukraine, Marie Yovanovitch.
The president was attending a roundtable discussion with several Republican governors on Monday, Dec. 16, and was asked by a reporter if he had spoken with Giuliani regarding his last visit to Ukraine. Giuliani's work in Ukraine also reportedly prompted federal prosecutors in NY to investigate whether the former mayor broke federal lobbying laws.