Direct flights from Christchurch to Los Angeles will cost triple the price compared to travel between the two cities a year ago.

American Airlines is preparing for flights to commence from January 2022, if the international borders open between the two countries.

Flights can already be purchased on the airline's website, with most selling for between $2000 and $2500 return.

That is a far cry from the $982 it would have cost in June last year, according to Faredetective.com data for connecting flights via Auckland.

Christchurch Airport announced American Airlines' plans on social media.

"From the South Island to the States ... American Airlines are preparing for direct flights between Christchurch and LAX from January if international borders are open. We can't wait to welcome them to CHC," a post on its Facebook page said.

American Airlines announced in September 2019 it would launch direct flights from Christchurch to Los Angeles, as well as from Auckland to Dallas-Fort Worth.

They were expected to take off in October last year but were put on hold due to Covid-19.

At the time of the 2019 announcement, the airline said the new routes are a direct result of the approved joint business with Qantas, which delivers new customer benefits like enhanced code-share opportunities and increased frequent-flyer benefits for American and Qantas customers.