MEXICO CITY: Mexican low-cost airline Viva Aerobus has agreed to purchase 1 million liters of sustainable aviation fuel (SAF) from Finland’s Neste (NESTE.HE), the companies said on Monday.

The fuel will be used on Viva Aerobus flights from Los Angeles to Guadalajara, Mexico City and Monterrey, the companies said in a statement.

The deal is “one of the most significant purchases (of SAF) from a Latin American airline,” Neste U.S. President Chris Cooper told Reuters. The contract’s value was not disclosed.

SAF is made from feedstocks such as animal waste and crop residues, and is more expensive than conventional fuel but considered key in reducing carbon emissions from air travel.

Rival Aeromexico has flown a handful of flights using SAF, while another Mexican competitor, Volaris (VOLARA.MX), has said it is exploring sustainable fuel options.

“It’s something we’re actively working on,” Volaris executive Dionisio Perez-Jacome told Reuters this month.

Viva Aerobus and Neste said a blend using around 35% SAF mixed with conventional jet fuel would power the flights, which are expected to take off in the second half of the year.

Cooper did not specify how many flights the SAF would fuel.

Supply of the biofuel has largely been limited to the United States and Europe so far, though Latin America has shown interest.

Neste spoke with Mexican airport operator ASA about the possibility of importing SAF to the country, the producer said.

Mexico would need to offer incentives to promote the switch to SAF as other countries have done, he said. “The desire for Mexico to become more sustainable will come from its leaders,” Cooper added.

Mexican President Andres Manuel Lopez Obrador, an energy nationalist, has poured billions of dollars into state-owned oil company Pemex during his administration, including opening a new refinery.

Pemex has faced intense international pressure to clean up its operations after recording massive methane leaks and excessive gas flaring.