Utah Republican Sen. Mitt Romney used his farewell address to the U.S. Senate to urge other lawmakers to put unity first in the face of stubborn partisanship.

“My life’s work has been a group affair,” Romney, who also served as governor of Massachusetts and the GOP’s 2012 presidential nominee, said in his address.

“I will leave this chamber with a sense of achievement. But in truth, I will also leave with the recognition that I did not achieve everything I had hoped,” Romney said.

“Among other things, the scourge of partisan politics has frustrated repeated efforts to stabilize our national debt. Without the burden of the interest on that debt, we would be able to spend three times as much as we do on military procurement,” he continued.

“Three times as many aircraft, three times as many ships, three times as many drones, spacecraft, cyber defenses. Or alternatively, we could spend double the amount we spend on Social Security benefits every month. Our national credit card is almost maxed out, and America risks becoming debt poor.”

Romney said his “biggest surprise in the Senate has been how much I enjoy the other senators on both sides of the aisle” but acknowledged he won’t miss “the myriad meaningless votes” or “10-minute votes that last an hour.”

As he prepares to leave the Senate, where he has served as one of President-elect Donald Trump’s most vocal Republican critics, Romney also appeared to toss a few veiled shots at Trump.

“There are some today who would tear at our unity, who would replace love with hate, who deride our foundation of virtue, or who debase the values upon which the blessings of heaven depend,” he said on the floor.

“Now, I’ve been in public service for 25 years. I have learned that politics alone cannot measure up to the challenges we face,” Romney stated.

WATCH: