Pyongyang has vowed to strengthen its nuclear force “in quality and quantity” and to expand the role of its intelligence agency, North Korean state media said on Friday.In a meeting of the Workers’ Party’s Central Military Commission on Thursday, North Korean leaders discussed plans to modernise the country’s armed forces, with Supreme Leader Kim Jong Un saying that only a strong military could guarantee “true peace,” per the KCNA news agency.”The meeting suggested tasks and ways for expanding in a many-sided way the functions and missions of the General Reconnaissance and Intelligence Bureau, which plays a pivotal role in controlling the potential enemies’ threats and gathering key information, and enhancing its capability of military reconnaissance and intelligence activities in a radical way,” KCNA reported.The commission also laid out plans to accelerate the building of modern naval bases and to upgrade combat systems, per the agency.The US’s Congressional Research Service says Pyongyang has been developing its nuclear programme over the last decade, posing an increased threat to the US and East Asia.Pyongyang has carried out six confirmed nuclear weapons tests since 2006.It comes after a North Korean soldier was reportedly taken into custody in South Korea after crossing the Korean demilitarised zone last month.South Korea’s Joint Chiefs of Staff said in a statement that the military had “secured custody of one North Korean soldier in the central front” and that authorities were investigating the details, according to Yonhap news agency.The demilitarised zone is one of the world’s most tightly secured borders, heavily fortified with barbed wire, land mines and extensive surveillance.South Korea’s Ministry of Unification says that more than 34,000 North Koreans, including 899 military personnel, have defected to the South since its records began in 1998.