The mayors of Hiroshima and Nagasaki voiced their disappointment Tuesday over Japan's decision to endorse the U.S.-India nuclear pact.

The 45-member Nuclear Suppliers Group, which includes Japan, reached a unanimous consensus earlier this month to endorse the bilateral pact.

The approval by the NSG allows India to engage in the trade of nuclear materials and technology for civil use, even though India has not signed the Nuclear Nonproliferation Treaty.

"There are voices of confusion and protest in Hiroshima and Nagasaki" regarding the government's approval of the deal, Hiroshima Mayor Tadatoshi Akiba told reporters after meeting with Vice Foreign Minister Mitoji Yabunaka in Tokyo.

According to Akiba and Nagasaki Mayor Tomihisa Taue, Yabunaka assured them Japan still believes in strengthening the NPT and the decision to approve the U.S.-India deal was made only after the utmost consideration.

But Taue said Yabunaka's accounts were "not convincing" and argued that the government has highlighted only the positive side of the nuclear deal while ignoring its perils, including the possibility of nuclear proliferation.

Foreign Minister Masahiko Komura said earlier in the day that Japan backed the pact to propel India's use of nuclear energy.

As mayors of the only cities to have experienced nuclear attacks, Taue and Akiba said they could not give their consent to the deal.