The chief of staff continued "they're not bad people".
"In retrospect, I wish I had been here from Day 1 ... in some cases, in terms of staffing, or serving the president, that first six months was pretty chaotic and there were some people hired that maybe shouldn't have", Kelly said.
Kelly additionally told NPR that he spends up to eight hours a day with Trump and thinks he's a "super smart guy" who made the right move in withdrawing the USA from the Iran nuclear deal. "He always listens", he said.
Asked if it was a "cloud" handing over the presidency, he said: "There may not be a cloud, but certainly the president is, you know, somewhat embarrassed, frankly". But he told NPR he thinks Trump is "a super-smart guy".
The probe which has already drawn guilty pleas from Trump associates and led to the indictment of his campaign chair and a raid on his personal lawyer also can lead to awkward small talk when Trump tries to sit down with a foreign leader.
Kelly also kept up his tough line on immigration, even as he said people with temporary protected status who have been here for decades should get citizenship.
Summit likely to be held in Singapore, not Panmunjom
Speaking to the media on the tarmac at Joint Base Andrews Air Force Base, Kim Dong Chul said his release felt "like a dream". And there are a number of things - provocative actions, for example, from North Korea , would not be received well.
The chief of staff added many undocumented immigrants come from countries where "fourth-, fifth-, sixth-grade educations are kind of the norm".
"They don't integrate well; they don't have skills". They don't speak English; obviously that's a big thing.
Before he took on the role of chief of staff, Kelly was the secretary of the Department of Homeland Security.
Questions were raised about Nielsen's tenure after the New York Times reported that she had considered resigning after Trump criticized her at a meeting on Wednesday for what he said was her failure to secure USA borders. A DHS spokesperson told the newspaper that reports of Ms. Nielsen being close to resigning are "false".
Trump has pursued his crackdown on legal and illegal immigration since becoming president, promising to strengthen the nation's borders and to build a wall along the U.S. -Mexico border. "I share his frustration".