The Australian foreign minister, Alexander Downer, says the Solomon Islands government could destroy the regional assistance mission, or RAMSI, if it tampers with the act allowing it to operate.
Mr Downer says if the act is substantially changed to remove legal immunities granted to mission members then the mission would be destroyed.
His comments comes amid a year-long row over the Solomons attorney-general, Julian Moti, who is wanted in Australia to face child sex charges.
The Solomons prime minister Manasseh Sogavare has said his government will review the Facilitation of International Assistance Act governing RAMSI operations.
Mr Sogavare has rejected a Pacific Islands Forum review team's report that endorsed RAMSI's operations and recommended the Act did not need amending.