European Commission President Ursula von der Leyen and Chilean President Gabriel Boric have agreed a deal on lithium to make electric vehicle batteries.
Chile is estimated to have more than a third of the world's reserves of lithium.
Lithium is key to several countries' goal of moving away from fossil fuels in the face of the climate crisis, with the use of electric cars whose batteries are made from lithium.
The European Commission has pledged 225 million euros to help the country develop the green hydrogen industry and help secure Europe's demand for renewable energy.
Von der Leyen, who has already visited Brazil and Argentina during her Latin American tour, which will also take her to Mexico, signed a memorandum of understanding in Buenos Aires on 13 June on raw materials, including lithium, whose demand in Europe "will grow 12-fold by 2030," she said.
Argentina, Bolivia and Chile make up the so-called 'lithium triangle', with almost 65 per cent of the world's reserves.
The visit takes place one month ahead of the EU-CELAC summit, focusing on cooperation between the EU-Latin America and the Caribbean.