The Bank of China (BoC) announced on Tuesday that it will lend 691 million U.S. dollars to Venezuela's top oil producer to finance the survey of mineral deposits in the country.

According to a deal signed by BoC, CITIC Group and Petroleos de Venezuela S.A.(PDVSA), the money will fund CITIC Group to conduct geological surveys and study the feasibility of developing gold and copper ores in the country.

Details of the agreement have not been unveiled.

The deal came after China and Venezuela vowed to enhance cooperation in finance and mining among other fields in a joint declaration issued on Monday during Chinese President Xi Jinping's two-day visit to the country.

PDVSA is the biggest state-owned enterprise in Venezuela as well as the largest company in Latin America. The oil giant raked in 121 billion U.S. dollars in sales revenue last year.