Sept 12 (Reuters) - An understanding between Iran and Oman does not provide for the immediate reopening of the Strait of Hormuz but establishes the basis on which it could reopen, an Iranian source told the semi-official Tasnim news agency on Saturday.

The source said the arrangement would be a step towards Iran exercising sovereignty over the strait and that its reopening depended entirely on the United States meeting Tehran's conditions.

(Reporting by Dubai newsroom, Editing by Louise Heavens)