Construction continues on the Louis Armstrong New Orleans International Airport North Terminal Project and entrance road in Kenner, La. Wednesday, Jan. 18, 2017. Mayor Mitch Landrieu and the New Orleans Aviation Board (NOAB) announced a five gate expansion of the bringing the total number of gates from 30 to 35.

The new terminal planned for Louis Armstrong International Airport — larger than initially envisioned in order to accommodate the city's bustling tourism market — is now slated to open by early 2019, a few months later than earlier forecast, at a cost of nearly $1 billion, city and aviation officials said Thursday.

The revised timeline and price tag were announced Thursday by the airport's interim director, Mark Reis, and quickly approved by the New Orleans Aviation Board.

The terminal was previously expected to open by October 2018, but recent design changes, including the addition of five gates, have pushed that date back, officials said.

The latest estimate for the new North Terminal puts the total price tag at $993 million, about $178 million more than when it was first planned in 2013. The project is being paid for through a combination of bonds funded by fees on the airlines and state and federal money.

The updated cost includes about $136 million to expand the terminal to 35 gates. That figure has climbed by nearly 25 percent since the move to add another five gates was first broached last fall. The extra $26 million is slated to create more space in the terminal as well as for airport operations, such as ramp space for airplanes and facilities for handling baggage.

Some of the $178 million total additional cost, officials said, results from changes in scope to the project in order to accommodate the city's recent traveler growth, which has increased more than was projected when the new terminal was planned in 2013.

"We knew from the get-go that this was an extremely expedited project, but if you get the choice of being hard-headed and holding onto a date that had a good purpose to it, or delivering what the city and the region truly needs, that's a pretty easy decision to make," Aviation Board member Roger Ogden said.

More than 11.1 million passengers — counting both those who landed and those who departed — went through the New Orleans airport in 2016, the highest number in its seven-decade history.

The number of departing passengers grew twice as fast in 2016 as officials had expected, and airlines have added about 7 percent more seats this year than last year, officials said.

By 2019, when the new terminal is now expected to open, the airport expects that the number of passengers flying out of New Orleans will be about 18 percent higher than was expected for that year in 2013.

The city described the design changes as tweaks to ensure the facility can accommodate the growth in business.

For example, the airport's initial plan was to buy about a dozen new jet bridges and reuse the ones from the present terminal. Instead, as the airlines' schedules have gotten busier, that option has become less viable, officials said, so they will buy all new ones. Also, they said, having a fleet of jet bridges all from the same manufacturer should cut down on future maintenance costs.

Another operational shift toward improving efficiency in the terminal's design involves using more kiosks and relying less on traditional counters.

Although they'd long aimed to have the new terminal open by 2018, in time for the city's tricentennial, airport officials said Thursday that passenger traffic has accelerated faster than forecast and that changing the design sooner rather than later would be less costly in the long run.

Rather than open the terminal in two phases as the work was finished, local officials consulted with the airlines and decided that would create too many logistical challenges.

"It is far safer, far less risky, with far better customer service, to in fact open the entire complex at once," Reis said Thursday.

Despite the delayed opening date, officials said preliminary work so far is proceeding on schedule.

Airport officials are waiting for final design work on the terminal to be completed, as well as additional regulatory approvals, which could come next month, and could begin construction within weeks.

In addition to 35 gates, the roughly 972,000-square-foot terminal will have a 2,190-car parking garage, a central utility plant and a ground transportation staging area.

Parts of the existing facility, including the parking garages, also will become part of the new complex.

Follow Richard Thompson on Twitter, @rthompsonMSY.