MOSCOW - The United States should give South Korea more leverage in relations with North Korea if it wants Seoul to play a more active role in facilitating denuclearization talks, Moon Chung-in, a South Korean special presidential adviser for unification, said on Thursday.

“The US should give some sort of leverage to Seoul such as a more flexible operation of inter-Korean economic exchange and cooperation,” the adviser said, as quoted by the Yonhap news agency.Moon stressed it would be a “herculean task” for the South Korean leader to act as mediator, given that Pyongyang considered Seoul as Washington’s ally.