(dpa) - South Korea Thursday reaffirmed its support for United Nations sanctions against North Korea by refusing entry to weapons-related officials from the communist country and calling for Pyongyang to return to international negotiations. The government said it will prevent entry of any North Koreans suspected of having links to nuclear and other weapons programmes into South Korea, Unification Minister Lee Jong Seong told a parliamentary committee in Seoul, reported Yonhap news agency. The unification minister said inspection of goods and materials shipped to the North have been increased to prevent the supply, sale or transfer of luxury goods in an attempt to curb what some have described as "disgusting spending" by leader Kim Jong Il, according to Yonhap. The announcement comes a day after Pyongyang threatened Seoul with punitive counter measures if it went along with "US-led moves on international sanctions." Also in response to the threat South Korea called on North Korea to unconditionally return to six-party talks over its nuclear weapons programme. "As the government has already clarified, North Korea's nuclear test was a serious threat to stability and peace on the Korean Peninsula and in Northeast Asia," a unification ministry spokesman said, reported Yonhap.