The Chicago Department of Buildings permit allows occupation of the 339-unit hotel portion of the condo skyscraper that begins four floors underground and reaches to the 23rd floor of the building.

"We're glad to have this done and excited to get the hotel up and running," Donald Trump Jr., of the Trump Organization, told the Chicago Tribune.

The permit allows Trump to notify buyers they can close on their units beginning in late January.

Real estate observers will closely watch the pending closures amid a poor real estate market.