Passage: The main U.S. contribution to the FANK effort came in the form of the bombers and tactical aircraft of the U.S. Air Force. When President Nixon launched the incursion in 1970, American and South Vietnamese troops operated under an umbrella of air cover that was designated Operation Freedom Deal. When those troops were withdrawn, the air operation continued, ostensibly to interdict PAVN/Viet Cong troop movements and logistics. In reality (and unknown to the U.S. Congress and American public), they were utilized to provide tactical air support to FANK. As a former U.S. military officer in Phnom Penh reported, "the areas around the Mekong River were so full of bomb craters from B-52 strikes that, by 1973, they looked like the valleys of the moon."On 10 March 1972, just before the newly renamed Constituent Assembly was to approve a revised constitution, Lon Nol announced that he was suspending the deliberations. He then forced Cheng Heng, the chief of state since Sihanouk's deposition, to surrender his authority to him. On the second anniversary of the coup, Lon Nol relinquished his authority as chief of state, but retained his position as prime minister and defense minister.

Question: What were the two positions Lon Nol ultimately did not give up despite losing chief of state?
prime minister and defense minister