Senior Chinese and Japanese diplomats traded barbs over Tokyo's nuclear capabilities during a U.N. session, media reports said Wednesday.

At the First Committee of the U.N. General Assembly held in New York on Tuesday (local time), China argued that Japan has a massive stockpile of plutonium that could be quickly used for the production of nuclear weapons. "Over the years, Japan has accumulated a huge amount of sensitive nuclear materials, giving rise to grave risks both in terms of nuclear security and nuclear proliferation," Beijing's Ambassador for Disarmament Affairs Fu Cong was quoted as saying in a speech. Japan is known to have around 47 tons of plutonium.

Japan immediately refuted China's claim.

The country's disarmament envoy Toshio Sano stressed it is using the nuclear program for purely peaceful purposes as it undergoes regular inspections by the International Atomic Energy Agency.

Japan sticks to the policy of "not making, possessing, and bringing in" nuclear weapons, he stressed.

The argument represents a rivalry between China and Japan over regional hegemony. The Northeast Asian giants are locked in a longstanding territorial row. (Yonhap)