Four seasoned stateswomen are leading a historic charge to become the first-ever female United Nations Secretary-General.

As public debates wrap up in New York, candidates Michelle Bachelet, Rebeca Grynspan, María Fernanda Espinosa, and Carolyn Rodrigues-Birkett have laid out aggressive visions to overhaul the international body amid unprecedented global polarisation.

The other two male candidates are former president of Senegal Macky Sall and Argentinean career diplomat Rafael Grossi.

UN Secretary-General Candidate Michelle Bachelet explained.

"And the key task for the next Secretary General will be to defend, preserve, and improve the organisation, including through continuous reforms in order to ensure that the UN delivers ever more and better. And I do that in very challenging times.”

Another candidate, María Fernanda Espinosa, shared her views.

"I think there are three reasons why I believe I am the right person to serve as the Secretary General of the United Nations. Number one: because I have led this House. You elected me as president of the General Assembly, and in that role, I worked with every member state. I listened to every voice. I built consensus even in the most difficult times."

Rebeca Grynspan also weighs in.

"Because we, nations large and small, can uphold the charter as our anchor in a turbulent world. Because we see drones cross boundaries that troops never did. Because we see the price of bread rise due to conflict far away. And because people are losing trust in the capacity of this organisation to deliver peace in a more dangerous, more complex world."

Carolyn Rodrigues-Birkett added: “The United Nations over these last eight decades has served humanity well, but it is now at a crossroads – the proliferation of conflicts, lack of implementation of the sustainable development goals, a liquidity crisis, and an increase in humanitarian needs. Reform to make this organisation more efficient, more effective, and more agile is now an imperative."