Prime Minister Julia Gillard was playing politics when she picked Brisbane to play host for the 2014 G20 summit, top officials of New South Wales said on Wednesday.

Sydney would have been the logical choice, according to NSW State Planning and Infrastructure Minister Brad Hazzard, calling it as "the only true world city of Australia."

He decried the choice of the Queensland city as Ms Gillard's way of shoring up her chances of attracting votes in the state following the humiliating defeat suffered earlier this year by the Labor state government of former Premier Anna Bligh.

"It would appear that Julia Gillard is quite prepared to use the world's leaders as her own political play things by taking them to Brisbane in an effort to shore up the Labor vote in Queensland," Mr Hazzard was reported by ABC as saying.

But the prime minister insisted on Wedneday that her decision was based on logistics and not on politics and that she had forged an understanding with Queensland Premier Campbell Newman for the state government to provide for the summit's security requirements.

It was also understood that Queensland will shoulder some of the bills for the November 2014 summit that will gather together leaders of the world's most prosperous economies.

The price as far as the federal government is concerned is $370 million but Queensland has yet to commit specific figures.

The only hint that Mr Newman can offer for now is that the state government "is not in a position to contribute a significant amount of funding toward the cost of hosting the G20 Leaders' Summit."

He pointed to the growing financial problem bedevilling the state, which the premier noted, was the result of the mismanagement left behind by the previous Labor administration.

Notwithstanding, Ms Gillard stressed that "we will be looking to Queensland to assist."

"Of course this means that other cities are disappointed but I do believe it is important that when Australia puts our face to the world that there are a number of cities that are part of that face and we have got a number of world-class cities," the prime minister was reported by The Australian as saying.

She explained that by the time that G20 leaders will be in Australia, Brisbane appears to be more ready compared to other key cities in the country, including Sydney.

Federal Treasurer Wayne Swan defended Ms Gillard's choice, stressing that the event will come to Australia for the first time so it's a must that the country showcase its best offering for the world to see.

"I think Brisbane in particular is the snapshot of our economy more broadly," Mr Swan told ABC.

"And certainly in terms of Brisbane and Queensland, the logistics here are excellent, the convention centre and the airport were particularly important in those considerations," he added.

And this early, it appears that Ms Gillard's move has attracted good vibes from key Queensland personalities, with Brisbane Lord Mayor Graham Quirk hailing her announcement today as a major boost for the city.

"There is no bigger international event than the G20 in terms of meeting of government leaders, and from that point of view it really does show Brisbane has come of age," Mr Quirk told ABC.

Also, business leaders welcomed Brisbane's hosting of the global event as "an opportunity to have a major stimulus to (the) local economy."

Still, Mr Hazzard is firmly convinced that the federal government should have opted for Sydney.

"It is the city that can best showcase Australia to the world and particularly to the G20 leaders," the NSW official said.