"While strengthening our nuclear war deterrent, we need to do everything in order to build the most powerful military," North Korea’s state news agency KCNA quoted Kim as saying on Wednesday.
Kim made the pledge as he delivered his closing speech at the ruling Workers’ Party congress, the first held in five years, which came to an end after eight days of policy discussions on Tuesday.
The massive ruling party congress was held amid a struggling economy in the face of persisting US-led sanctions over Pyongyang’s nuclear and ballistic missile programs and the coronavirus pandemic.
Earlier, Kim described the United States as "the fundamental obstacle" to the development of North Korea and the country’s "foremost, principal enemy." He said Washington’s hostile policy toward Pyongyang "will never change, whoever comes to power," without mentioning Biden by name.