Spanish airline Iberia said Wednesday it would offer its clients discounted Covid-19 tests before their flights, as a growing number of nations require incoming passengers to show a negative result to enter.

Under an agreement signed with health services firm Quironprevencion, Iberia passengers will be able to take a polymerase chain reaction (PCR) virus test at one of its clinics for 20 percent less than the "market price", it said in a statement.

A standard PCR test, which provides results within 48 to 72 hours, costs between 130 euros ($150) and 240 euros in Spain, according to Spanish consumer association OCU.

Iberia said this will "facilitate the procedure for all those travelling to destinations requiring passengers to present a PCR test certificate carried out a few hours or days before the date of arrival."

Iberia is part of International Consolidated Airlines Group (IAG), alongside British Airways, Vueling and Air Lingus.

Airlines have been hammered by the pandemic and are pressing governments to introduce alternatives to blanket travel restrictions that are still hampering a traffic recovery.

Air traffic is down 70 percent this year when compared to 2019, according to the sector's main global body, the International Air Transport Association (IATA).

It has called for a reliable Covid-19 testing system for passengers to be put in place in order to give governments the "necessary confidence to open their borders" and allow passengers to feel comfortable booking flights.