While Prime Minister Naoto Kan promised that Japan would participate in the United Nation's nuclear safety summit in September, he did not clarify whether he himself would be present at the high-level meeting, U.N. chief Ban Ki Moon said Monday.

With a low support rate and calls to resign coming from both the opposition and his own ruling Democratic Party of Japan, whether Kan will attend the U.N. meeting in New York on Sept. 22 is being closely watched.

"I told him that sharing such invaluable experiences and lessons learned from this Fukushima accident, as well as the tsunami recovery process, would be very valuable for the international community, and reiterated the importance of the prime minister's participation (in the September meeting)," Ban said. "The prime minister assured me that the Japanese government will contribute and participate proactively, but we will have to continue our consultations on this matter."