While praising Japan's efforts to provide humanitarian aid, visiting U.N. High Commissioner for Refugees Filippo Grandi said Monday the ongoing Rohingya crisis in Myanmar and Bangladesh is the "most serious refugee crisis since the '90s."

At the same time, however, Grandi asked Japan to improve its strict refugee examination process, which has often come under international criticism.

"If you look at the speed" at which Rohingya refugees are fleeing Myanmar, "if you look at the violence that (the refugees) have endured before crossing the border, especially women and children, and if you look at the magnitude, the immensity of the needs in Bangladesh . . . I think this is the most serious refugee crisis since the '90s," Grandi told a news conference at the Japan National Press Club in Tokyo.