Marine Minister Emma Hardy said a bill will be introduced to enable ratification of the pact to establish protected areas in international waters.

The spending review is expected to set out tough spending limits for departments other than health, defence and education.

The investment is expected to be spent on projects such as fixing level crossings, building new stations and upgrading railway lines.

The troops are only in the city to protect federal property, officials said, as President Donald Trump clamped down on immigration protests.