Secretary of Commerce Robert Mosbacher indicated the United States may soon lift the trade embargo against Vietnam. He made his remarks Friday before U.S. businessmen, who urged him to renew the trade ties that were cut when the Communists won the Vietnam War in 1975. Mosbacher said lifting of the embargo was ``still over the horizon but, depending on the talks, it could appear shortly.'' In a letter addressed to him, the American Chamber of Commerce in Thailand said U.S. companies are ``losing out on the potential Vietnam offers on many economic fronts.'' Washington has said a settlement of the Cambodian war must be reached before relations are normalized with Vietnam, which backs Cambodia's Communist government. However, the United States reversed a longstanding policy last month, announcing it would enter into direct negotiations with Vietnam on Cambodia.