Timor Leste has placed an order with Austal for another two Guardian-class patrol boats.
The AU$29.7 million (US$23.1 million) contract increases the total program from 19 to 21 vessels.
The Pacific Patrol Boat (PPB) program creates inter-governmental co-operation to aid regional security in the South Pacific by helping to secure maritime borders in that region.
Austal Chief Executive David Singleton said the first boat is on schedule for launch at the end of May, with construction under way on two others.
Construction will begin on a fourth vessel in June.
The PPB contract for 19 vessels was awarded in May 2016 and is worth AU$305 million.
