The top presidential security advisers agreed to enhance cooperation between the two allies to toughen sanctions and pressure on North Korea, Seoul officials said.

South Korean Foreign Minister Yun Byung-se and his Japanese counterpart Fumio Kishida also had a telephone conversation and reaffirmed that they would work together closely to curb the North's provocative acts. 

During the talks, the ministry said that Yun delivered the South's analysis of the latest missile launch by the North to Kishida who responded that it is a "grave threat that cannot be tolerable" in that the ballistic missiles fell in its exclusive economic zone.

They also promised to work closely together through diverse channels including their bilateral talks and the UN Security Council to apply "strong" and "effective" pressure on the North down the road, the ministry noted.

Meanwhile, Seoul's top nuclear envoy Kim Hong-kyun held back-to-back telephone talks with his Japanese and US counterparts, according to the ministry.

The North fired four projectiles from an area near the North's Dongchang-ri long-range missile site at 7:36 a.m. and they flew about 1,000 kilometers before splashing into the East Sea.

Japan reportedly said three out of the four missiles fell into its exclusive economic zone, some 250 km west of Akita Prefecture. (Yonhap)