"Leader of the Democratic People's Republic of Korea (DPRK), Kim Jong-un, concluded the 9th Congress of the Workers' Party of Korea (WPK) in Pyongyang on Wednesday, vowing to bolster the country's nuclear capabilities in response to what he called the 'confrontational' and 'reckless' behaviour of the United States. Images released by the Korean Central News Agency (KCNA) on Thursday show Kim addressing the Congress to applause from delegates, before leaving the April 25 House of Culture. According to KCNA, Kim reaffirmed Pyongyang's determination to advance its nuclear technology to deter what it calls Washington's 'hostile policy' toward the DPRK and 'aggressive blocs' led by the United States in the Asia-Pacific region. "The DPRK's nuclear force is now fulfilling its mission of physically and strongly deterring any war of aggression in a responsible manner," the agency reported. During the party's Congress, Kim was re-elected as secretary-general of the ruling WPK, extending his 15-year leadership. He assumed power following the death of his father in 2011 and has since expanded the country's nuclear weapons programme, positioning Pyongyang as a growing strategic challenge for the West, particularly the United States. The Ninth Party Congress, held from February 19–25 and convened roughly every five years, is expected to set out the next phase of the DPRK's weapons development. Ahead of the gathering, the country unveiled what it described as a new range of nuclear-capable rocket launchers."