A Wellington woman who led the push for an international ban on cluster bombs is celebrating today as her dream is realised.

The 2008 Convention on Cluster Munitions came into force today, two years after being adopted internationally, and six months after it received its 30th ratification.

Human Rights Watch arms division adviser Mary Wareham said today the ban was "a victory for the campaign", in which New Zealand was "involved from the get-go".

But there was still work to be done on ridding the world of the bombs which had a massive impact on civilians -- especially children -- with states like the USA and Israel yet to sign up to the convention, she said.

Cluster bombs, which can contain hundreds of "bomblets", pose risks to civiians both during and after attacks. Unexploded bomblets can kill or maim civilians, many of them children, long after a conflict is over.

The bombs have been in use since the 1960s, dropped on countries across Asia, Africa, the Middle East and Europe, with a lasting legacy in places including Vietnam, Cambodia and Laos.

The US and Britain also dropped the bombs over Iraq in 2003.

But it was Israel's use of cluster bombs against Hezbollah in Lebanon in 2006 that was the catalyst for talks to ban the bombs.

In the final 72 hours of the war, when it was clear a resolution would be reached, the bombings by Israel left more than one million unexploded cluster munitions, which were still affecting the Lebanese people today.

More recently still, both Russia and Georgia dropped cluster munitions during their 2008 conflict.

New Zealand was involved in the idea of a ban from the beginning - part of "the core group", alongside Austria, Ireland, Mexico, Norway and Peru, Ms Wareham said.

One round of talks was held in Wellington in February 2008, followed by the negotiations of the final convention in May 2008, and the first signing in December that year.

The New Zealand Parliament passed the Cluster Munitions Prohibition Act in 2009, and the Government quickly ratified the treaty.

In February this year, the treaty finally received its 30th ratification, making it a binding international law fronm today.

Though 108 countries had now signed up to the ban, only 38 governments had ratified the convention, which banned them from using or producing cluster munitions.

UN Security Council permanent members USA, China and Russia, along with Israel and India, were among the states yet to sign the treaty.

The five states were also yet to sign the 1997 Ottawa Treaty banning landmines -- another convention led by New Zealanders.

But the Obama administration was currently reviewing the landmines ban, and it was hoped they would make swift steps on both treaties, Ms Wareham said.

Disarmament Minister Georgina te Heuheu said the convention coming into force made today "a landmark day".

"New Zealanders should be proud of the leading role their country has had in bringing this ban about," she said, calling on states which had not yet signed it to do so as soon as possible.

"Many thousands of civilians are injured or killed in the course of normal daily activities by these weapons. Particularly tragic is the fact that around one third of cluster munitions casualties are children," Mrs te Heuheu said.

New Zealand kicks off global celebrations of the ban at Wellington's Civic Square at midday today, followed by a screening of Ms Wareham's short documentary, Cluster Bombs: Banned in New Zealand.