Chad's economy has long been handicapped by its landlocked position, poor transportation network, inadequate natural resources, and ongoing political turmoil. Chad economy is mainly based on agriculture. Fishing, firming and livestock constitute the major types of agricultural activities. Agriculture constitutes around 20% of the total GDP. The chief minerals of the country are uranium and natron. Petroleum is found in the southern part. Oil, cotton, cattle, and gum arabic are Chad's major exports. Imports include machinery, transportation equipment, industrial goods, foodstuffs, and textiles. Chad relies on foreign assistance and foreign capital for most public and private sector investment projects. Chad's chief trading partners are the United States, France, Cameroon, and China.