President Donald Trump can't seem to stop talking about his predecessor. Just this week, Trump kind of, sort of, walked back claims that former President Barack Obama wiretapped his New York City tower in the run-up to election day.

"That really covers surveillance and many other things," Trump said in a Fox News interview. "Nobody ever talks about the fact that [the words 'wires tapped'] was in quotes [in the tweet], but that's a very important thing."

Throughout the years, Trump has done everything from (repeatedly) cast doubt Obama's birthplace to question what was "going on" with the then-president's response to police shootings.

But Obama has not shied away from slamming Trump in turn. Listed below are eight things the 44th president has said about Trump throughout the years.

1. On Trump's birther claims, at the 2011 White House correspondents' dinner, which the now president attended

"Donald Trump is here tonight. Now I know that he’s taken some flak lately. But no one is happier, no one is prouder to put this birth certificate matter to rest than The Donald. And that’s because he can finally get back to focusing on the issues that matter: Like, did we fake the moon landing? What really happened in Roswell? And where are Biggie and Tupac?"

2. About Trump's presidential credentials, also at the 2011 White House correspondent's dinner

"All kidding aside, obviously, we all know about your credentials and breadth of experience. For example, no, seriously, just recently in an episode of 'Celebrity Apprentice,' at the steakhouse, the men's cooking team did not impress the judges from Omaha Steaks. And there was a lot of blame to go around, but you, Mr. Trump, recognized that the real problem was a lack of leadership and so, ultimately, you didn’t blame Little John or Meatloaf—you fired Gary Busey. And these are the kinds of decisions that would keep me up at night. Well-handled, sir. Well-handled."

3. On the rigors of being president in 2015

"Being president is a serious job... It's not hosting a talk show or a reality show, it's not promotion, it's not marketing, it's hard. It's not a matter of pandering and doing whatever will get you in the news on a given day."

4. On Trump's tweets

"As a general rule, I don't pay attention to Mr. Trump's tweets."

5. On Trump's Twitter account... and the nuclear codes

"Now, you may have heard that—this was just announced, I just read it, so I can’t confirm it's true, but—this campaign has taken away his Twitter. In the last two days, they had so little confidence in his self-control, they said 'We're just gonna take away your Twitter.' Now, if somebody can't handle a Twitter account, they can't handle the nuclear codes. If somebody starts tweeting at 3 in the morning because SNL made fun of you, you can't handle the nuclear codes."

6. Saying Trump wasn't prepared for the presidency while commenting on the then Repulican nominee's attack on a Muslim soldier's family

"The notion that he would attack a Gold Star family that made such extraordinary sacrifices on behalf of our country, the fact that he doesn't appear to have basic knowledge of critical issues in Europe, the Middle East, in Asia, means that he's woefully unprepared to do this job."

7. On the prospect of Trump winning the White House

"I would feel deeply frustrated, not because of anything he's said about me, but because I would fear for the future of our country."

8. Commenting, through a statement from spokesman Kevin Lewis, on Trump's travel ban restricting entry into the U.S. for seven Muslim-majority countries.

"With regard to comparisons to President Obama's foreign policy decisions, as we've heard before, the president fundamentally disagrees with the notion of discriminating against individuals because of their faith or religion."