Before a motley audience of international notables, the Prime Minister, who is in New York for the United Nations General Assembly, was named World Statesman of the Year.

The award was presented on behalf of the Appeal of Conscience Foundation - which campaigns for religious freedom and human rights - by the veteran US former secretary of state Henry Kissinger.

Rock star Bono, Queen Rania of Jordan, and New Israeli defence minister Ehud Barak were among the audience as Mr Kissinger praised Mr Brown for his “vision and dedication” in handling the world economic crisis.

“His leadership has been essential to our ability to overcome the moment of danger,” said Mr Kissinger.

In an article in the New York Times today, Mr Brown called on world leaders to show “collective resolve” to address the five challenges of climate change, economic recovery, terrorism, nuclear proliferation and poverty, and create “the first truly global society”.

Comparing the current situation to the post-war period of rebuilding after 1945, the Prime Minister said that this week’s meetings will determine whether the world witnesses “a new era of collaboration” to deal with these problems .

“The next six months will test international co-operation more severely than at any time since 1945,” said Mr Brown.

“That may seem strange to say after a year of global crisis that has demanded unity on an immense scale, yet five urgent challenges confront us and we cannot delay our responses.

“Crucial meetings this week in New York and Pittsburgh will determine by next spring whether a new era of collaboration is possible.

“We cannot solve these problems immediately, of course, but momentous decisions are demanded now toward halting climate change, renewing economic prosperity, fighting terrorism, ending nuclear proliferation and overcoming poverty.”

Global leaders must “stay the course” on delivering fiscal stimulus to the fragile world economy through 2010 and must give a “clear commitment” to future jobs, growth and stability, said Mr Brown.

International agreement must be reached on the “Afghanisation” of Afghanistan, by building up the country’s security forces and civic institutions and handing power to its people.

And he urged fellow world leaders to follow him by offering to attend the UN climate change talks in Copenhagen in December, where a deal on a post-Kyoto carbon-reduction framework is currently “hanging in the balance”.

On nuclear proliferation, Mr Brown highlighted Britain’s proposal for states which renounce nuclear weapons to be given access to civil atomic energy through an international uranium bank.

And he called for funding from the rich world to deliver free medical treatment to the world’s poorest people, particularly pregnant woman and children.

Mr Brown wrote: “After 1945, the world - fresh from a devastating conflict - summoned its energies to build a new international order.

“Now we are being tested again. In the days and months ahead, our collective resolve must hold across all the challenges I have outlined.

“If it can, then something bigger and even more lasting than the great reconstruction of the post-war era is possible: the creation of the first truly global society.”