The U.S. Export-Import Bank has voted to loan $500 million to finance development of Mongolia’s massive copper-gold Oyu Tolgoi mine—one of the world’s biggest—which, upon completion, will generate 30% of GDP in a country already enjoying booming mining sector development.

The mine, in the South Gobi desert 550 km south of the capital Ulaanbaatar, is an open-pit and underground copper operation containing copper, gold and silver. It’s operated by Oyu Tolgoi LLC, jointly owned by Turquoise Hill Resources Ltd. of Canada and Erdenes Oyu Tolgoi LLC of Mongolia. Global miner Rio Tinto holds a majority stake in Turquoise Hill.

The Export-Import Bank is a federal agency creating U.S. jobs by private export financing free to American taxpayers. Since 2008, the bank has earned $1.6 billion for taxpayers by providing mechanisms, including working capital guarantees, export-credit insurance and financing, to help foreign buyers purchase U.S. goods and services.

In 2012, the bank approved $35.8 billion in authorizations—a record amount, including more than $6.1 billion supporting small-business sales. Total authorizations have supported $50 billion in U.S. export sales and 255,000 American jobs in communities nationwide.