"Such reports are nothing more than fabrication ... as they are always based on the so-called testimonies of "defectors" who provide fabricated information to earn their living or are compelled to do so under duress or enticement", its Geneva mission said in a statement.
Bribery is "an everyday feature of people's struggle to make ends meet", said the report, entitled "The price is rights".
The report includes interviews with 214 North Korean escapees.
The missile test, North Korea's first since 2017, served as a clear warning of leader Kim Jong Un's frustration at the state of talks with the U.S., which have been deadlocked since Trump walked out of their Vietnam summit early in February, Lewis told CNN earlier this month. "So I think President Trump is making a big mistake here in thinking that his own personal charm or his relationship or friendship with Kim Jong-un is going to be enough to make a deal that will achieve our objective of ultimately denuclearizing the Korean Peninsula.
But what the U.S.is focused on here...is in trying to negotiate a peaceful end to the North Korean WMD program".
Kazianis suggested the tests were a way for Kim Jong Un to demonstrate resolve to the generals and the party cadre that surround and support him.
The U.N. has also said 4 out of 10 North Koreans suffer from chronic food shortages, which continue to occur because Pyongyang prioritizes the military before the food needs of ordinary people.
Those who try to earn money this way "face arrest and detention", the United Nations report noted.
The president said that while his "people think it could have been a violation..." It denounced what it called a "vicious cycle of deprivation, corruption and repression".
The defectors originate from different parts of the North, including Ryanggang and Hamgyong Provinces. They were the first to be cut from the public distribution system that collapsed in 1994, leading to a starvation estimated to have killed up to 1 million, it said.
"We have said many times and we will continue to reiterate that the economic sanctions will remain in place until we're there", she said. The then-20-year-old had to bribe her way out of detention. "Even though the state has granted some room to the market, people still have to pay bribes to get by in much of the system".
Many North Koreans seek a living through rudimentary markets, while paying bribes to get out of duties at official state-assigned jobs, according to the report.
Others bribe border guards to cross into China, where women are vulnerable to trafficking into forced marriages or the sex trade, it added.
Bachelet urged North Korean authorities to stop prosecuting people for engaging in legitimate market activity and to allow them freedom of movement within the country and overseas. Combined with the seizure of a North Korean tanker suspected of violating worldwide sanctions on the secretive state, these developments have undermined improving relations between the two historic adversaries.
Trump also said he did not believe the missile tests violated a United Nations resolution-passed in 2006 and reinforced by a second in 2009-imposing sanctions on North Korea and demanding the nation "not conduct any further nuclear test or launch of a ballistic missile".