In short two things according to the Swedish department of Justice.
1. Ecuador require the Swedish prosecutors to grant Assange refugee status, but only the Migration Agency can do that, not the department of Justice or the prosecutors office.
2. Ecuador want guarantees that Assange will not be extradited to the US in the future. In Sweden extradition requests are handled by the supreme court and the prosecutor-general and a promise in advance never to extradite someone cannot be given.
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