Labour says New Zealand should use its close relationship with Australia to influence the United Nations Security Council response to the crisis in Syria.
On Monday, Australia assumes the presidency of the Security Council.
Labour Foreign Affairs spokesperson Phil Goff said the council is deadlocked on a resolution that would allow countries to take all necessary means in response to the use of chemical weapons in Syria.
He said that through Australia, New Zealand could suggest a resolution requiring all UN member states to immediately cease providing weapons to Syria.
He said blocking the sale of weapons could be a first step to ending the conflict, rather than potentially increasing it with a full military strike.
