(MIA), but only 1,200 Americans were reported to have been killed in action with no body recovered. Only 591 American POWs were returned during Operation Homecoming in early 1973. Many American MIAs were pilots who were shot down over North Vietnam or Laos. Investigations of these incidents have involved determining whether the men involved survived being shot down; if they did not survive, then the U.S. government considers efforts to recover their remains. The U.S. POW and MIA issue greatly affected attempts at normalizing diplomatic ties between the U.S. and Vietnam in the aftermath of the Vietnam War As of 2007, the U.S. government listed 1,763 Americans unaccounted for in Southeast Asia, including 1,353 in Vietnam. Since 1973, 883 Americans have been accounted for, including 627 in Vietnam. Additionally, the U.S. Department of Defense has confirmed that of the 196 individuals who were officially considered "last known alive", the U.S. government has determined the fate of all but 31. The U.S. considers achieving the fullest possible accounting of Americans missing and unaccounted for in Indochina to be one of its highest priorities with Vietnam. Severance of diplomatic ties and attempts at normalization Following the Vietnam War, Vietnam pursued the establishment of diplomatic relations with the United States. This was initially to obtain US$3.3 billion in reconstruction aid, which U.S. President Richard Nixon had secretly promised after the Paris Peace Accords were signed, in the form of a letter offering a specific figure. In June 1975, Vietnamese Premier Phạm Văn Đồng, speaking to the National Assembly, invited the U.S. to normalize relations with Vietnam and to honor its commitment to provide reconstruction funds. Representatives of two American banks—the Bank of America and First National City Bank—were invited to Hanoi to discuss trade possibilities, and American oil companies were informed that they were welcome to apply for concessions to search for oil in Vietnamese waters. However, the U.S. government neglected Đồng's call for normalized relations, because it was predicated on reparations, and the American political climate in the wake of the war precluded the pursuit of such an outcome. The U.S. also applied a trade embargo against Vietnam in 1975. In response to Vietnam, the administration of U.S. President Gerald Ford imposed its own precondition for normal relations by announcing that a full accounting of American POWs and MIA, including the return of any remains, would be required before normalization attempts. No