South Korea's Yonhap News Agency says North Korea appears to have used its recent missile launches to demonstrate progress in its tactical nuclear weapons development.

Yonhap said the test firings may be an attempt by the North to show it can mount small nuclear warheads on various missiles.

The report also said North Korean leader Kim Jong Un emphasized his position to rejecting dialogue with the United States. Yonhap said there are views that the North's recent moves are a signal that Pyongyang will press ahead with its seventh nuclear test.