NEW YORK >> Rex Tillerson, who served a turbulent term as secretary of state under former President Donald Trump, was called as a government witness today at the trial of a Trump ally accused of leaking intelligence to the United Arab Emirates.

Tillerson testified that he barely knew the defendant, Tom Barrack, once the chairman of Trump’s inaugural committee, or anything about his relationship with the UAE. Instead, he spelled out how he would meet with Trump on a regular basis to discuss foreign policy, emphasizing that the sensitive conversations were supposed to stay confidential.

“You really don’t want outside parties to have access to that information and use it to their advantage,” Tillerson told a New York City jury.

Prosecutors have alleged Barrack provided inside information on how Trump administration officials viewed a UAE-led blockade of neighboring Qatar. Tillerson testified he had advised Trump not to engage with the UAE on the issue, saying, “We needed to let them sort that out on their own.”

Tillerson also described one encounter with Barrack where he “called over to my office … and expressed an interest in an ambassadorship,” he said. But Trump didn’t embrace the idea, “so that was the end of it,” he said.

On cross-examination, Tillerson acknowledged having disagreements with Trump, but stayed clear of criticizing the former president. He said they sometimes played “good cop-bad cop” in their public statements about adversaries like North Korea.

The former Exxon Mobil CEO is the highest-profile witness so far at the federal trial of Barrack, a billionaire private equity manager and Trump confidant who’s accused of secretly working as a foreign agent for the UAE.

Barrack, 75, has pleaded not guilty to that charge, along obstruction of justice and false statements counts.

In 2018, Trump dumped Tillerson via Twitter, abruptly ending the service of a Cabinet secretary who had reportedly called the Republican president a “moron” but refused to step down, deepening disarray within the Trump administration.

Trump and Tillerson clashed on several foreign policy issues, including whether the U.S. would stay in the 2015 agreement to restrict Iran’s nuclear efforts, a deal Tillerson favored. Trump announced in 2018 that the U.S. was withdrawing from the agreement.

So far, prosecutors have relied on a trove of emails and other communications they say demonstrate how Barrack’s “unique access” to Trump to manipulate his campaign — and later his administration — to advance the interests of the UAE. The efforts included helping arrange an Oval Office meeting between Trump and Abu Dhabi’s Crown Prince Sheikh Mohammed bin Zayed Al Nahyan in 2017.

At the same time, UAE officials were consorting with Barrack, the energy-rich Gulf state rewarded him by pouring millions of dollars into his business ventures.