Former secretary of state Rex Tillerson has criticized alleged actions that have triggered an impeachment inquiry into President Donald Trump, saying using US influence for personal gain is "wrong."
Tillerson, a former oil executive who was unceremoniously fired by Trump in March last year, was asked about the scandal in an interview with the PBS Newshour broadcast Monday.
Without using Trump's name or going into details of the incident, Tillerson said: "Clearly, asking for personal favors and using United States assets as collateral is wrong."
"So if you're seeking some personal gain and you're using, whether it's American foreign aid, American weapons or American influence, that's wrong, and I think everyone understands that," he said.
House Democrats have launched an impeachment inquiry into Trump over allegations that he held up military aid to press Ukraine to dig up dirt on political rival Joe Biden.
Trump has denied any wrongdoing and accused the Democrats of waging a witch-hunt against him.
The alleged "quid pro quo" occurred well after Tillerson was dismissed by Trump via Twitter.
Tillerson has since offered critical views on Trump, including saying last year that he was obliged to stop the tycoon turned president from taking actions that were illegal.
Trump has voiced anger in response and described Tillerson as "dumb as a rock."