Japan needs to redouble its efforts to fight human trafficking and assume a leadership role in the international community that matches its economic power, a senior U.S. administration official said in a recent interview.

"I was disappointed," John Miller, director of the U.S. State Department's Office to Monitor and Combat Trafficking in Persons, said of Japan's response to the issue.

"Japan is a leader, a leading democracy in the world, one of the wealthiest democracies with tremendous resources and I think there was a gap, a huge gap, between the level of the challenge and the resources and efforts that were being devoted to the challenge," he told Kyodo News.

Miller visited Japan in February as part of a five-nation Asian tour to meet local government officials, nongovernmental organization members, women who were trafficked and others to prepare for an annual report to be released in June on global conditions of human trafficking.