The Defence Minister, Brendan Nelson, has returned from a short visit to Baghdad saying Australian troops in al Muthanna, in southern Iraq, would stay until at least next year.
Labor says the decision shows the Howard government's military commitment in Iraq is now limitless.
But Mr Howard says the government has always indicated an additional commitment was possible.
"The Labor party knows what we're saying and the Australian people know what we're saying - that our forces will come out when their job has been completed.
"That day is getting closer but I can't say when it is, and I'm not going to make myself a hostage to a particular time or date."