The first meeting of parties to a U.N. treaty banning nuclear weapons, set to be held next January, may be pushed to the spring so that it takes place after a rescheduled U.N. conference on nuclear nonproliferation, diplomatic sources said Tuesday.

The review conference on the Nuclear Non-Proliferation Treaty, held every five years in New York, has already been pushed back multiple times from its original date of April last year to August this year due to the coronavirus pandemic, but there are talks of postponing it again to the beginning of next year.

Photo taken May 26, 2021 shows the Peace Memorial Park in Hiroshima, western Japan, with the Atomic Bomb Dome seen in the background. (Kyodo)

The Treaty on the Prohibition of Nuclear Weapons, which is the first international pact outlawing the development, testing, possession and use of nuclear weapons, came into effect in January this year with the support of many non-nuclear states.

Its first meeting, which must be held within one year of coming into force, is currently scheduled for January next year in Austria. Japanese survivors of the 1945 atomic bombing are also expected to attend.

With the momentum for nuclear disarmament waning due to the pandemic, the international community stands at a critical juncture concerning whether nuclear-armed states will curb their nuclear expansion.

As it will be unrealistic to hold both conferences in January next year, proposals have been made to postpone the first meeting of the nuclear ban treaty by several months or hold the meeting in January as scheduled but postpone substantive discussions until after the NPT review conference.

There are strong calls among countries supporting the nuclear weapon ban treaty to hold the NPT conference as soon as possible, with many likely eager to also observe the discussions at the review conference attended by the nuclear powers.