NEW YORK -- Rex Tillerson, who served a turbulent term as secretary of state under former President Donald Trump, was called as a government witness Monday at the trial of a Trump ally accused of leaking intelligence to the United Arab Emirates.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.On cross-examination, Tillerson acknowledged having disagreements with Trump, but stayed clear of criticizing the former president.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."