John Key's up! pic.twitter.com/wtXFEqxdxI
He said the Syria situation showed that the council's permanent members had assumed more power than simply the right to veto council resolutions - and the threat of veto alone was enough to stop matters going to the Security Council.
"They also appear to have privileged access to information and can stop the Council from meeting if it does not serve their collective purpose."
New Zealand is bidding for a seat on the Security Council in 2015 and 2016, and Mr Key said: "New Zealand is not advocating revolution, but we are asserting the Council can and must do better in the way it conducts its business. That is the approach New Zealand will bring to the Security Council if we are elected next October."
"There is no point in joining the Security Council simply to make up the numbers. Sometimes, you have to speak up and shine a light on what is going on, or not going on, even when that may be inconvenient to others."
He said the UN was a place for the countries of the world to meet, talk and try to find solutions, but often those discussions were so arcane they hid the issues they were meant to resolve.
ON SYRIA:
He said the failures of the UN were due to the member states and their leaders, rather than the UN itself. The first was Syria, which had failed to adhere to human rights conventions. The leaders of the permanent five members were also to blame.
"This organisation would not also have been a powerless bystander to the Syrian tragedy for over two years if the lack of agreement among the Security Council's Permanent Members had not shielded the Assad regime."
Mr Key called for the Security Council to take strong action by passing against Syria for its use of chemical weapons.
"These are war crimes."
He said he was pleased that the Security Council had accepted a report finding unequivocally that chemical weapons were used in Syria.
"Those responsible must be brought to account. Those that try to cast doubt on the report's conclusions make themselves look foolish and do a disservice to the UN.
Mr Key said the council should respond to the use of chemical weapons.
"It must find a means to hold those responsible to account, and establish an effective mechanism for the destruction of those weapons in line with the proposal developed by the United States and Russia. The resolution must also provide for the protection of the civilian population."
Mr Key's speech comes just before the Security Council is due to meet to discuss Syria - and the United States has claimed Russia has agreed to a draft resolution which would require Syria to hand over its chemical weapons, albeit without any sanctions if it did not comply. That would require a further resolution, which Russia could veto.
Despite his criticism of the Security Council, Mr Key said that as a small, geographically isolated nation, New Zealand still had a "strong preference" for a multilateral, rules-based approach such as that of the UN, or, on trade issues, the TO.
"Rules and standards set internationally offer us the greatest certainty and the greatest protection. We draw strength from global agreements and from the collective commitment they represent."
He also pushed for progress on the Middle East peace process. "There can be no resolution without the Israeli and Palestinian peoples both being assured of viable homelands within secure borders."
Closer to home, he said New Zealand looked forward to the restoration of democracy in Fiji "with intense interest and cautious hope."
And in clear bid to set out New Zealand's credentials for the Security Council bid, he spoke about New Zealand's peacekeeping efforts, including Timor-Leste, Afghanistan and the RAMSI mission to the Solomon Islands.
