New Zealand's Labour Party says there is no reason the government should not support the Marshall Islands lawsuit against the nine countries with nuclear weapons.
The Marshall Islands government is suing the United States and the eight other nuclear-armed countries for failing their obligations to disarm
It is filing the lawsuits in the International Court of Justice and the US Federal District Court.
The Labour Party's disarmament spokesperson, Maryan Street, says she will be asking the foreign minister to support the suits.
"Here is a fundamental and critical issue that our government can take some leadership on. Anybody who stands up for a case in front of the International Court of Justice should not find diplomatic barriers in their way, because it is justice."
The Labour Party's Maryan Street.