Jan 2 (Reuters) - The United States has dropped Burkina Faso from its AGOA trade preference program citing deep concerns over "unconstitutional change" in government in the West African country, the U.S. Trade Representative's (USTR) office said on Sunday.Frustrations over the government's inability to curb an Islamist insurgency spurred two military coups in Burkina Faso in 2022.The U.S. African Growth and Opportunity Act (AGOA) provides sub-Saharan African nations with duty-free access to the United States if they meet certain eligibility requirements, such as eliminating barriers to U.S. trade and investment and making progress toward political pluralism.The USTR's office said Burkina Faso had failed to meet the requirements of the AGOA statute and would be given "clear benchmarks" for a pathway toward reinstatement to the trade program, adding that Washington would work with the Burkinabe government.Just before Christmas, Burkina Faso's military government ordered a senior United Nations official to leave the country, a decision that was contested by the U.N.."