Mr Howard cited Zimbabwe's human rights record and economic turmoil to explain his decision.
"The living standards in the country are probably the lowest of any in the world, you have an absolutely unbelievable rate of inflation.
"Whilst it pains me both as a cricket lover and as somebody who genuinely believes these things should be left to sporting organisations... it leaves me with no alternative."
Cricket Australia had been reluctant to cancel its September tour to Zimbabwe because that would have made it liable to pay a minimum $2m fine levied by the sport's international governing body, the International Cricket Council (ICC).
However, an ICC statement released before the Australian government forced the cancellation of the tour indicates Cricket Australia would not be fined....