United States "very actively" asking N.Korea to return to talks - S.Korea

The United States is "very actively" trying to persuade North Korea to come back to negotiations, South Korea's national security adviser said on Sunday, as a year-end North Korean deadline for U.S. flexibility approaches.

South Korea was taking North Korea's deadline "very seriously", the adviser, Chung Eui-yong, told reporters, at a time when efforts to improve inter-Korean relations have stalled.

North Korean leader Kim Jong Un in April gave the United States a year-end deadline to show more flexibility, and North Korean officials have warned the United States not to ignore that date.