Yoon Hee-keun said he felt "limitless responsibility about public safety" over what happened. He said there would be a full investigation amid growing public demands for accountability for the tragedy.
Mr Yoon said police had received calls earlier in the evening expressing concern about the number of people crammed into the narrow streets of the Itaewon district.
It is understood the first call to the police emergency number came at 6:34pm local time – hours before people began to be injured in the crush. There were ten more calls over the next three-and-a-half hours.
Mr Yoon said more police than usual had been deployed to the area due to an expectation of larger crowds than usual, following restrictions during the pandemic – but admitted the response had been inadequate.
He said: “The action of the police was insufficient. To clarify the circumstance and responsibilities, intense internal inspection will be conducted, without exceptions.”
Mr Yoon said lines of inquiry into how the incident began, including witness reports that a group of people had started pushing the crowd down the alley, while another party goer had urged others to push, were being investigated. He said rumours the crowd had gathered amid claims that a celebrity was due to appear had not been confirmed.
Officers are also looking into a local hotel’s use of the path for Halloween booths and and additional terrace, which it is believed could have made the alley even narrower than usual.
In a National Assembly meeting, Interior Minister Lee Sang-min described the situation as “difficult” and apologised.
"It is very sad for me as a father who has a son and daughter … it is difficult to express in words how unreal this situation is, and it is difficult to accept this situation," he said.
The Foreign and Commonwealth Office confirmed it had not received any requests for help from British citizens in South Korea. The department said the South Korean authorities had said no UK nationals were involved.
More than 20 foreign nations were killed in the incident, including people from Norway, France, the US and China.
Witnesses of the crush had described people falling on one another, suffering severe breathing difficulties and falling unconscious.
They also recalled rescuers and ambulances failing to reach the crammed alleys in time because the entire Itaewon area was extremely packed with slow-moving vehicles and a crowd of party goers clad in Halloween costumes.
After the disaster, police launched a 475-member taskforce to find its cause.
Senior police officer Nam Gu-Jun told reporters that officers had obtained videos taken by about 50 security cameras in the area and were analysing video clips posted on social media. He said police had also interviewed more than 40 witnesses and survivors so far.
The death toll could rise as officials said 29 of the injured were in serious condition.