Asked about the appointments during a news conference that followed a solar farm groundbreaking, Christie dismissed the idea that the two were patronage hires.
The governor said he had not known Harris, a fellow Republican, until the nominating process began.
"It's not like he's an old buddy I'm putting into a job," he said.
Of Kwon, one of several people Christie brought to the administration from the U.S. Attorney's Office, the governor said he got a raw deal.
"The state Senate made an enormous mistake not putting Phil Kwon on the Supreme Court," he said.
The appointments of Harris and Kwon, who both were rejected as Supreme Court justices amid questions about their background and qualifications, follow the placement of another high-level Christie aide, appointments counsel Michele Brown, to head the Economic Development Authority (EDA).
Brown, who earned $141,000 as a cabinet officer, will see her salary increase to $225,000. She once took a $46,000 loan from Christie while they were federal prosecutors after Brown's husband lost his job. The loan was later repaid, the administration has said.
The EDA also created a second top job, effectively splitting the post held by outgoing EDA chief Caren Franzini into two positions.
Sen. Loretta Weinberg (D., Bergen), who attended the solar dedication, said that Harris and Kwon probably are qualified for their new roles, but certainly were not hired after a nationwide talent search or after responding to an ad in the New York Times.
"It depends on your definition of patronage," she said.
If Harris and Kwon had been confirmed to the state's top court, both would have been paid $185,482 annually.
Christie also defended a recent decision to veto Democrat-sponsored legislation that would have increased accountability at the Port Authority by requiring hearings before any toll increase could be voted on.
Christie called the bill politically motivated and said he would consider such a measure only if the state's other agencies and authorities were included.
Weinberg said drivers who soon will pay $13 to cross the George Washington Bridge deserve more accountability.