Russian authorities say next year's World Cup will cost $600 million more than previously planned.

There was no immediate explanation from organizers or the Russian government for the latest cost rise, published in a government decree Tuesday and signed by Prime Minister Dmitry Medvedev.

Costs have risen by 34.5 billion rubles ($600 million) to 678 billion rubles ($11.8 billion), the decree states.

Of that, 57.6 percent comes from the federal budget. There is another 13.6 percent from regional government budgets, with a further 28.8 percent from ''legal entities,'' a category which can include both private and state-run companies.

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