US President Donald Trump said on Friday he wanted to appear in court, expressing full conviction of his innocence, following the public testimony of nine witnesses in the ongoing probe into his impeachment in preparation for his removal.

"I think it's hard for them to isolate you if they don't have anything at all," Trump said in a telephone interview with Fox News today.

The president suddenly said that I "want a trial," but he refused to answer the following questions on this comment.

The president spent much of his hour-long interview attacking several key witnesses, claiming that he did not know others, even Gordon Sundland, who donated $ 1 million to Trump's political campaign and then became ambassador to the European Union.

Trump criticized Democratic Rep. Adam Schiff, who leads the investigation, calling it "corrupt" and "elusive" and playing a "foolish role." He accused House Speaker Nancy Pelosi of being "crazy like a bed bug."

The president also appeared to have criticized the dismissed ambassador to Ukraine, Mary Jovanovich, who allegedly refused to comment on his photo at the embassy in Kiev. "This was not an angel, this woman," he said.

Though his role has become more controversial in Ukrainian affairs, Trump defended his personal lawyer, Rudy Giuliani, as a "great warrior against crime" when he explained why he was being used as a special envoy to manage diplomatic affairs with Ukraine.

Giuliani's remarks, as well as testimonies from a number of witnesses, showed he was excited that Ukraine was investigating Trump's political rival Joe Biden.

Trump faces charges of using his authority to slander a local political rival.