Venezuelan President Nicolás Maduro on Sunday accused the United States of trying to seize his country’s vast oil reserves by increasing its military presence in the Caribbean.

In a letter to the Organization of the Petroleum Exporting Countries (OPEC), Maduro said Washington seeks “to take control of Venezuela’s massive oil reserves, the largest on the planet, through deadly military force.”

He added that the threat endangers “regional and international peace, security and stability” and poses risks to Venezuelan oil production and the global oil market.