Bank of Japan board member Yutaka Harada said Wednesday that unemployment needs to fall further if the country's stubbornly stagnant inflation rate is to pick up, while also advocating for continued monetary easing.

His comments, made in a speech to business leaders in Kanazawa, Ishikawa Prefecture, came after government data last week showed the nationwide jobless rate fell to 2.2 percent in May, its lowest level in a quarter of a century.

"One often hears the question of why prices are not rising even though the unemployment rate has fallen to around 2.5 percent, well below 3.5 percent, which until recently was widely regarded as the structural unemployment rate. My answer to this question is simple: the decline in the unemployment rate is insufficient," he said.