Korea Gas signed an agreement with Gazprom in September to import 7.5 million tonnes of gas. The attempt to get North Korea's consent to build a pipeline in its territory comes as ties between the two countries grow chilly after South Korean President Lee Myung-bak, who took office in February, vowed to take a tougher line on its neighbour than his predecessors. A pipeline via North Korea is expected to be more economical, although a subsea link from Vladivostok to Samcheok on South Korea's eastern coast is a possible route, Mr Choo was quoted as saying in Seoul.