Haruhiko Kuroda joked that his previous role running the Asian Development Bank was more exciting than the assignment he's taken on as governor of the Bank of Japan.

Kuroda, who's spearheaded massive monetary stimulus in Japan for more than four years but still faces an inflation rate near zero, was speaking Saturday during a seminar at the ADB's annual meeting in Yokohama, which wrapped up Sunday. He led the Manila-based development lender from 2005 until 2013.

Kuroda reaffirmed the BOJ's April forecast that inflation in Japan should reach the 2 percent target in around the fiscal year that starts in April 2018 and ends in March 2019. He added that the task is challenging.

Asked which job was harder, the ADB or the BOJ, Kuroda joked: "I can say it like this, the ADB presidency is certainly more exciting than governorship of Bank of Japan, but certainly central banking is sometimes more complicated and difficult."

The ADB gathering in Yokohama is the first time in a decade that the institution has had its annual meeting in Japan, its largest source of funding. It comes as a new China-backed development bank ramps up lending across the region.

The ADB's current president, Takehiko Nakao, said in an earlier interview that there has been more cooperation than competition with the Beijing-based Asian Infrastructure Investment Bank.

Japan and the U.S. both declined to join the AIIB, which now has 70 approved members, more than the 67 countries and territories that are part of the ADB.