A survey finds that more than 90 percent of South Koreans think the denuclearization of North Korea is not possible amid Pyongyang’s continued efforts to advance its nuclear capabilities.

According to the survey of one-thousand-43 people by the Chey Institute for Advanced Studies released on Monday, 91 percent of the respondents said the North’s denuclearization is not possible.

North Korea enshrined the right to use preemptive nuclear strikes to protect itself in a new law last year before amending its Constitution to bolster and expand its nuclear force this year.

Asked if the regime’s denuclearization is possible under the circumstances, more than 41 percent said that it is completely impossible, while nearly 50 percent said it is not possible, a stark change from the 77-point-six percent who said it is not possible in the same survey last year.

Asked if the United States will exercise its nuclear deterrence in the event of emergency as the North is capable of attacking the U.S. mainland thanks to developments in intercontinental ballistic missiles, submarine-launched ballistic missiles and multiple independently targetable reentry vehicles, over 60 percent said that the U.S. will not, while 39 percent said otherwise.