Poland has finalized a deal to acquire a second batch of 180 South Korean tanks under a 2022 agreement that will eventually see Warsaw boost its arsenal with almost 1,000 of the armored vehicles.

South Korea, Japan and the United States conducted a joint air drill on Friday involving a U.S. B-52 strategic bomber and fighter jets of the three allies over international waters, the South's defence ministry said.

South Korea on Wednesday repatriated six North Koreans across the maritime border in the East Sea, months after they drifted into southern waters and were rescued.