According to the broadcaster, Suga said it at a parliamentary meeting when asked whether Prime Minister Shinzo Abe should still meet North Korean leader Kim Jong-un without preconditions even after Tokyo had lodged a protest against the ballistic missile firings in Pyongyang last Thursday.
Throughout May, North Korea carried out a series of projectile launches which Japan later identified as ballistic missiles. On Thursday, missiles were fired eastward from the province of North Pyongan, as confirmed by the US and South Korea.
They flew 420 and 270 kilometers (261 and 168 miles) respectively before hitting into the Sea of Japan, South Korea's Joint Chiefs of Staff (JCS) reported.
The launches occurred following a deadlock in the denuclearization negotiations between Pyngyang and Washington in Vietnam in February.