Thomas Barrack appears in Brooklyn Federal Court in Brooklyn, New York
Thomas Barrack, a billionaire friend of Donald Trump who chaired the former president's inaugural fund, exits the Brooklyn Federal Courthouse in Brooklyn, New York, U.S., October 3, 2022. Reuters

Tom Barrack, a onetime fundraiser for former U.S. President Donald Trump, took the witness stand in his own defense on Monday in his trial on charges of being an illegal foreign agent for the United Arab Emirates.

Federal prosecutors in Brooklyn said Barrack used his influence with Trump's election campaign and administration to push the UAE's interests in 2016 and 2017 without notifying the U.S. attorney general, as required by law. They say Emirati sovereign wealth funds invested $374 million in Barrack's private equity firm Colony Capital, now known as DigitalBridge Group Inc, in 2017 and 2018.

Barrack, 75, has pleaded not guilty. On the stand on Wednesday, he testified that sovereign wealth funds in Qatar - a UAE rival in the Gulf - were "unquestionably" more significant investors in fueling Colony's early growth than the UAE, and that Kuwaiti sovereign wealth funds also invested.

Barrack's defense has argued his close relationship with Qatar shows he was not an Emirati agent. Last week, former U.S. Treasury Secretary Steven Mnuchin testified that Barrack urged him to get Trump to back Qatar in a 2017 blockade brought by the UAE, Saudi Arabia and others.

To prove Barrack was a UAE agent, prosecutors must prove he agreed to act under the Middle Eastern country's direction or control.

Under questioning by his lawyer, Michael Schachter, Barrack said it would have been "impossible" for him to act subject to the "direction or control" of investors such as Kuwait or Qatar, because other investors would not tolerate it.

"If you are acting for them, you're not going to act for us," Barrack said.

Prosecutors were expected to cross-examine Barrack once Schachter finished his questioning.

During the monthlong trial, prosecutors have showed jurors text messages and emails indicating that Emirati officials provided feedback to Barrack on what he should say in television interviews and an opinion article about U.S. policy toward the Middle East in 2016 and 2017, and gave input about what Trump should say about energy policy in a 2016 presidential campaign speech.

Barrack's lawyers have previously argued his interactions with Emirati officials were part of his job running Colony Capital. They have said that even in instances where his interests may have aligned with the UAE's, Barrack was acting on his own volition.

In a post on his Truth Social platform on Sunday night, Trump said he did not believe Barrack was a UAE agent, and that Barrack never spoke to him about speeches or "what to say on this subject."

"Tom Barrack is a highly respected businessman whose DREAM was to see PEACE IN THE MIDDLE EAST, a very good and noble thing," Trump wrote. "He is being unfairly persecuted only because he is a supporter of 'Trump.'"