A three-day review conference on the nuclear test-ban treaty ended at the UN headquarters in New York on Friday, calling for early ratification by the US, China, Israel, Iran and seven other countries and stressing benefits of the pact for tsunami early-warning systems.
In a final declaration, participants from 117 countries said cessation of all nuclear weapon-test explosions and all other nuclear explosions "constitutes an effective measure of nuclear disarmament and non-proliferation in all aspects."
"We note that significant progress has been made in signing and ratifying the [Comprehensive Test Ban Treaty - CTBT] which has achieved near universal adherence," the declaration said.
But it also noted with concern that the pact has yet to come into force nine years after it was adopted.
The CTBT cannot come into force until it is ratified by the required 44 states which had nuclear research or power facilities when it was adopted in 1996.
Only 33 have done so. The US, the world's leading nuclear power, Colombia, Egypt, Indonesia, China, Iran, Israel and Vietnam are among the remaining 11 countries that have not ratified
Diplomats fear that unless key countries like the US and China come into the fold, the treaty may well collapse.
"There's no change in the position of the US," said UN Under Secretary General for Disarmament Affairs Nobuyasu Abe, noting that there was no expectation that Washington would ratify it in the near future.
"We call upon all states which have not yet done so, to sign and ratify the treaty without delay," the declaration said, echoing an appeal made by UN chief Kofi Annan at the opening of the conference on Wednesday.
"The longer entry into force is delayed, the greater the risk that someone somewhere will test nuclear weapons," Annan warned. "That would be a major setback for the cause of non-proliferation and disarmament."
Participants also stressed the importance of building up an effective, global verification regime to ensure compliance with the treaty when it comes into force.
"We agree that in addition to its essential function, the CTBT verification system currently being built would be capable of bringing scientific and civil benefits, including for tsunami-warning systems and possibly other disaster-alert systems," the participants added.
A quake off the Indonesian island of Sumatra on Dec. 26 triggered huge waves that slammed into coastlines across the Indian Ocean, killing more than 270,000 people.
CTBT monitors detected the quake and immediately alerted both Indonesia and Thailand. Yet critics have accused countries of failing to act on the information quickly enough and not evacuating people from the coastlines.
The Vienna-based CTBT organization decided on March 4 to consider contributing to the tsunami-warning system.