VIENNA - The United Nations nuclear watchdog is seeking to gain access to sites in Myanmar, which rejected allegations by an exile group last year it was trying to develop atomic weapons, a diplomat familiar with the issue said.

Myanmar officials signalled during talks in September that inspectors of the International Atomic Energy Agency (IAEA) could come to the southeast Asian nation, which has initiated radical reforms after decades of authoritarian military rule.

The meeting on the sidelines of the IAEA's member state conference raised hopes of progress on the issue, the diplomat added, without specifying which facilities the Vienna-based UN agency may want to see. There was no immediate IAEA comment.

A exile group based in Norway said in mid-2010 that Myanmar had a secret programme dedicated to developing the means to make nuclear weapons, following up on similar allegations by defectors from the then reclusive state.  

The IAEA said at the time that it was looking into the report. Myanmar is a member of both the IAEA and the nuclear Non-Proliferation Treaty.

Myanmar's IAEA envoy, Tin Win, said in September the country did not have "enough economic strength" to develop atomic arms.

It has also previously denied the accusations.

A US-based think tank this week said allegations by the exile group and defector interviews claiming that Myanmar "had or has a nuclear weapons research programme remain unsubstantiated and poorly evidenced".

But, the Institute for Science and International Security (ISIS) said: "The international community must remain steadfast in its calls on (Myanmar) to fully commit to nuclear non-proliferation objectives and allow full verification of those commitments."