Wellington, April 11 NZPA - Costa Rica's president elect has called for the New Zealand Government to join it and other countries supporting a United Nations proposal to abolish nuclear weapons.

Laura Chinchilla said in a letter to Prime Minister John Key and Minister for Disarmament Georgina te Heuheu that both Costa Rica and New Zealand were "active in advancing cooperative security, human rights, disarmament and development internationally at the United Nations and other key forums".

UN Secretary-General Ban Ki-moon called for negotiations over the prohibition of nuclear weapons in a plan for nuclear disarmament supported unanimously last year by the 150 parliaments, including New Zealand's, comprising the Inter-Parliamentary Union.

Mr Ban has also circulated a draft nuclear abolition treaty to all governments as a guide to negotiations.

A group of experts led by New Zealander Alyn Ware prepared the draft convention, which was presented to Mr Ban by the Costa Rican and Malaysian governments.

Mr Key is attending a Nuclear Security Summit hosted by US President Obama this week, following Mr Obama's new policy restricting United States use of nuclear weapons.

The meeting of about 46 leaders would be very important as more countries sought to arm themselves with nuclear weapons, Mr Key said last week.