The leader of the International Campaign to Abolish Nuclear Weapons, which won last year's Nobel Peace Prize, has been denied a meeting with Prime Minister Shinzo Abe, Japanese nongovernmental organization Peace Boat said Monday.

ICAN asked the Japanese government twice since late December to arrange a meeting between Abe and Executive Director Beatrice Fihn during her ongoing visit to Japan, but the Foreign Ministry declined the request, citing a scheduling conflict, according to Peace Boat, a major steering group member of the Geneva-based organization.

Expressing disappointment that she would be unable to meet Abe during her first visit to Japan, Fihn said in Hiroshima she wants to talk with him about how the world can avoid a repeat of the devastation inflicted on Hiroshima and Nagasaki -- the two cities atom-bombed by the United States in 1945.

Fihn added she looks forward to meeting with the Japanese prime minister at the next opportunity.

Atomic-bomb survivors, known as hibakusha in Japan, expressed their disappointment.

"Does Prime Minister Abe understand the significance of ICAN winning the Noble Peace Prize? It is very regrettable to feel this difference of attitudes between the government and atomic-bomb survivors," said Hiroko Kishida, a 77-year-old hibakusha.

Chief Cabinet Secretary Yoshihide Suga, however, told media in Tokyo that a meeting was not arranged "due to a conflict of schedule. Nothing more, nothing less."

Abe departed Japan on Friday for a six-nation European tour and is set to return home on Wednesday. Fihn arrived in Japan on the same day as Abe's departure.

After visiting Nagasaki through Sunday, she delivered a keynote speech at an event held Monday in Hiroshima where some 340 people, including students and survivors of the atomic bombing, gathered.

She said there are divergent views on the U.N. nuke ban treaty between the people who live at the sites of the atomic bombs and the Japanese government and the gap in understanding must be narrowed, stressing all countries' participation in the treaty will be key to resolving the nuclear weapons issue.

In Hiroshima, Fihn laid flowers at the Peace Memorial Park's Cenotaph and listened to the testimony of 80-year-old hibakusha Keiko Ogura.

Fihn is scheduled to hold discussions with Japanese parliamentarians in Tokyo on Tuesday before leaving Japan on Thursday.

ICAN, founded in 2007, is a coalition of NGOs that involves about 470 groups from more than 100 countries.