"We must further strengthen the nuclear war deterrent while doing our best to build up the most powerful military strength," Kim said, as quoted by Rodong Sinmun, the official newspaper of the ruling party.
During his speech, Kim also called for fulfilling a new five-year economic development plan and said that he was "honoured" to be elected as the party's secretary-general.
After the closure of the congress, Kim paid tribute at the Kumsusan Palace of the Sun, which serves as a mausoleum for the country’s former leaders.
On Sunday, the Workers’ Party elected Kim as secretary-general, thus reviving the title that had been held by his father and grandfather. Soon after coming to power in late 2011, Kim was elected as the party’s first secretary.
In 2016, the party decided to replace the secretariat with the Executive Policy Council, and Kim received the title of chairman. Over the weekend, the secretariat was revived.