Republican U.S. presidential candidate Mitt Romney will announce his choice of a vice presidential running mate Saturday.

Romney's campaign office announced Friday night that the announcement will take place at about 9:00 a.m. in Norfolk, Virginia before the candidate begins a bus tour that is being called “The Romney Plan For A Stronger Middle Class.”

His campaign would not say who Romney has chosen. But the announcement will be made on board the retired battleship USS Wisconsin, prompting some pundits and analysts to speculate it could be Wisconsin Congressman Paul Ryan, the House Budget Committee chairman, who has the backing of many influential conservatives.

The Wisconsin is berthed in Norfolk as a display at the Nauticus maritime museum.