Former Exxon Mobil CEO and former U.S. Secretary of State Rex Tillerson arrives at New York State Supreme Court as an Exxon witness to testify as part of a trial in a lawsuit by New York's attorney general accusing the oil company of misleading investors about the risks of climate change regulations to its business in Manhattan, New York, U.S., October 30, 2019. REUTERS/Mike Segar/File Photo

HOUSTON (Reuters) - Former U.S. Secretary of State Rex Tillerson said on Saturday that Republicans and Democrats need to work together for the good of the United States, while avoiding a direct reference to the Democratic-led impeachment inquiry of President Donald Trump.

Tillerson, whom Trump fired in a tweet in March 2018 amid friction between the two over North Korea, Iran and Russia policies, has largely refrained from discussing politics publicly since leaving Washington.

Speaking in Houston at a fundraiser for the UCross Foundation, an artists and writers residency program, Tillerson urged a “civil and thoughtful discourse,” saying that the current political rancor is widely viewed as equal to that during the Civil War.

“Perhaps the arts can help the American people reconnect with their country and remember how precious this Republic is,” he said to an audience of about 250 people. Tillerson received the Wyoming-based organization’s inaugural Award for Visionary Leadership.

The former diplomat later declined to comment on the impeachment process under way in the U.S. House of Representatives. The inquiry focuses on Trump’s attempt to get the government of Ukraine to investigate his Democratic rival Joe Biden.

“I’m concerned for our country. Both sides have got to get their act together,” Tillerson said in a brief interview.

Since leaving the Trump administration, Tillerson, also the former chairman of Exxon Mobil Corp, has described the President as an undisciplined leader who did not like to read. Trump has criticized Tillerson as “lazy as hell” and “dumb as a rock.”