At the official opening of the facility, which doubles the size of the international and domestic departure areas, Mr English told about 75 invited guests the continued growth at the airport "demonstrates an optimism and a confidence about the [tourism] industry which, in theory, is under a bit of pressure".
"There have been discussions about the exchange rate - we all know how sensitive the tourism industry is to the exchange rate.
"Some of the [industry] are under a lot of pressure.
"Queenstown Airport has had a record year.
"This is a company that's continued to show confidence in the market."
The 570sq m expansion at the northeast end of the existing terminal allowed for extra security screening lanes and immigration booths as well as redevelopment of Air New Zealand's Koru Lounge at the mezzanine level.
The expansion also has provision for duty-free retail to double in size and store operator LS Travel Retail has flagged substantial plans for redevelopment and refurbishment by next winter.
Queenstown Airport chief executive Scott Paterson paid tribute to the project manager, architect and lead building contractor.
"Built in a very tight timeframe and in difficult weather conditions, the build is a testament to a great group of people working together and we at the airport applaud and thank all involved for their effort and diligence."
Mr Paterson said the original terminal had catered for 700,000 passengers, but during the past financial year more than one million passengers passed through the facility, which underlined the need to expand and provide visitors with an improved experience.
"Our airport clocked some record days during the winter with a dramatic 29% increase in flights over the same period last year.
"During August, we processed 122,998 passengers and the new international departures lounge was opened to coincide with the peak numbers.
"On just one day, passengers from six jets used the lounge over a two-hour period.
"Our busiest week saw 43 transtasman flights."
Growth was predicted to continue this summer with a 17% increase in inbound flights this January compared with January 2012, Mr Paterson said.
"The summer airline schedules predict even greater passenger numbers and the new facilities will undoubtedly come into their own."
This week, Jetstar announced it was adding weekly Queenstown-Sydney and Queenstown-Melbourne services. Air New Zealand recently announced it had increased Auckland-Queenstown services by 32%.
Virgin Australia had added 11,000 seats to and from Queenstown.
