Aramco and Siemens AG will sign an agreement Monday to build a pilot project for carbon capture and storage, as the Middle East’s biggest oil producer Saudi Arabia seeks new ways to tackle emissions.

“We believe direct-air capture will work, but needs more innovation and technologies to bring the costs down,” Aramco’s chief executive officer, Amin Nasser, said at an event Sunday in the Saudi capital, Riyadh, as he announced the project.

Extracting carbon dioxide from the atmosphere rather than sources of emissions, the direct-air method is the costliest application of carbon capture, according to the International Energy Agency.