Natalegawa, speaking at UN headquarters in New York, said Southeast Asian nations were in the process of completing negotiations before declaring a nuclear-free zone in the region.
"Having said that, it's very important to lock in and further appreciate the fact that now, for the first time, the nuclear-weapon states are on the same page in the issue (nuclear disarmament)," Natalegawa told reporters.
"Hopefully, combined with the CTBT and the Nuclear Non-proliferation Treaty, and support from countries in the region, we can create even a stronger momentum on nuclear issues," he said.
Natalegawa handed over the signed and ratified CTBT document to UN Secretary General Ban Ki-moon, which commits his country to not carrying out nuclear explosions anywhere in the world, including underground, underwater and in the atmosphere.//DPA