Johnson made eleven international trips to twenty countries during his presidency. He flew aboard Air Force One while in office. His October 1966 visit to Australia sparked demonstrations from anti-war protesters. One of the most unusual international trips in presidential history occurred before Christmas in 1967. The President began the trip by going to the memorial service for Australian Prime Minister Harold Holt, who had disappeared in a swimming accident and was presumed drowned. The White House did not reveal in advance to the press that the President would make the first round-the-world presidential trip. The trip was completed in only 112.5 hours (4.7 days). Air Force One crossed the equator twice, stopped at Travis Air Force Base, in Honolulu, Pago Pago, Canberra, Melbourne, Vietnam, Karachi, and Rome.