The airline had been leasing an older generation 737 from Europe to perform its flights - but the lease has expired. Samoa Airways was due to lease a new 737 Max 9 in late March. However, the airline has announced it has cancelled its lease in the wake of two fatal crashes and the global grounding of the Boeing aircraft.
Samoa Airways is now scrambling to find another plane to operate its international flights.
In an email to customers, the airline said: "Unfortunately our current lease upon which our flights have operated since November 2017 couldn't be extended, and with the worldwide grounding of the MAX 8 aircraft type, there is a huge shortage of narrow-body aircraft as airlines scramble to consolidate their schedules using their existing fleets and short-term leases from other operators.
The current plan appears to be an emergency lease of a 737 from Malaysian carrier Malindo Air. The airline said in a statement: "Samoa Airways and Malindo Air are working closely with the civil aviation authorities of Australia, New Zealand, Malaysia and Samoa to secure the required safety and regulatory approvals, which the carriers anticipate will come through towards the end of the first week of April."
The airline announced it was cancelling its services to Auckland, Brisbane and Sydney for the next few days from 2 April to 4 April, 2019.
The affected flights to Auckland include a return flight from Apia to Auckland on Tuesday, 2 April (OL731/OL732) and a return Apia to Auckland service on Thursday, 4 April (OL731/OL732).
Samoa Airways added "safety is of paramount importance and until the clearances have been obtained (for a new aircraft), we have unfortunately had to cancel some of our flights in the first week of April and re-route our customers on to other airlines to minimise any further disruption to their travel plans".
The worldwide 737 Max fleet was grounded after two similar fatal crashes involving an automated nose-down system that pilots were unable to control.