Prime Minister John Key says the veto powers of the UN Security Council's top five countries are standing in the way of human rights.
Mr Key takes to the stage at the Security Council tomorrow, as part of UN Leaders' Week in New York.
He wants restrictions on the power of veto given to permanent members Russia, France, the United States, Britain and China.
Something needs to change, he told the Paul Henry programme today.
"It's not a failed institution per say, the Security Council, it's an institution with failings," he says.
"It has failing because actually this is a time for leadership and the only body in the world that can really do that when it comes to Syria actually is the Security Council and it's [impertinent] because of the veto."
Mr Key's stance follows Russia vetoing an inquiry into the shooting down of Malaysia Airlines MH17, allegedly by Russian-supplied missiles.