PRESIDENT Clinton was the first of 65 signatories including the Tanaiste, Mr Spring of the new UN treaty banning nuclear weapons tests at a ceremony in New York yesterday, Writes Mark Brennock.
President Clinton later called for a new treaty to end the spread of chemical and biological weapons.
Mr Spring described the signing ceremony as "a major achievement for the international community".
The treaty bans nuclear testing and provides for on Site inspection in states suspected of violating its provisions.
It does not come into force however until it is signed by all 44 countries which possess nuclear energy.
India is among a small number of states that object to the treaty.
They argue that states that do not yet have nuclear weapons should not be prevented from developing them until the existing nuclear powers give stronger commitments on disarmament.
The treaty is the product of protracted negotiations in Geneva which ended in August when India vetoed the treaty.
Australia subsequently proposed a resolution at the UN General Assembly adopting the treaty, and this was passed by 158 votes to three (India, Bhutan and Libya) with five abstentions.
Mr Spring will meet the Indian Foreign Minister in New York today, and will urge his government to reconsider its refusal to sign.
The vast majority of the 185 UN member states are expected to sign the treaty in the coming months when their governments and legislatures have ratified it.
The 65 states which signed yesterday include the "Big five" permanent members of the UN Security Council (the US, Britain, France, Russia and China), Japan and all EU member states.
"Today was a particularly good day for disarmament and for the United Nations" Mr Spring said yesterday. "The European Union would urge all states to sign and ratify this important treaty."
The treaty was a landmark in the bid to control and eventually eliminate nuclear weapons. It testifies to the strength of international opinion opposing nuclear tests."
He said he hoped it would come into force at the earliest possible date.