WATCH: Ted Cruz, who once called Donald Trump a liar, isn’t comfortable defending his comments

Sen. Ted Cruz was clearly uncomfortable defending President-elect Donald Trump during an interview with Martha Raddatz on “This Week” on Sunday.

After talking with Cruz about the recent death of Fidel Castro and any potential role Cruz might play in a Trump administration, Raddatz replayed an old Cruz quote that clearly made the senator squirm.

During the Republican primary, the Texas senator called Trump a “pathological liar,” adding, “He doesn’t know the difference between truth and lies. He lies practically every word that comes out of his mouth. The man is utterly amoral. You know, morality does not exist for him.”

That clip was played during the interview. After that, Raddatz asked, “Do you regret any of those words?”

When Cruz attempted to shift focus away from his words by saying “it was a hard-fought campaign” and claiming that “my focus is on the country,” Raddatz tenaciously held on to her original question.

“I just want to go back to those words,” Raddatz asked, quoting Cruz’s line that Trump “‘lies practically every word that comes out of his mouth.’ Do you still think Donald Trump is a liar?”

Cruz continued his evasion, insisting that “I’m not going to re-litigate the past. I’m going to focus on the future. I’m going to focus on what’s in front of us and on fixing the problems we have.”

As Trump’s chief rival for the Republican presidential nomination this year, the two men began an acrimonious feud that often took ugly turns. When it came time for Cruz to follow tradition and endorse Trump for the presidency at the convention, he pointedly refused to do so, citing how Trump had insulted Cruz’s wife for her appearance and alleged that Cruz’s dad had played a part in assassinating President John F. Kennedy.

A few weeks later, he shifted gears and endorsed Trump, resulting in melancholy pictures like this one making the rounds on social media.

Watch Ted Cruz’s interview below: