Minister for Defence Christopher Pyne said the deployment supports Australia's economic and diplomatic pressure on North Korea.
"This is part of Australia’s commitment to deter and disrupt illicit trade and sanctions evasion activities by North Korea and its associated networks," Minister Pyne said.
"Australia continues to work with partners to maintain pressure on North Korea until it takes concrete, verifiable and irreversible steps to de-nuclearisation."
The P-8A is built specifically as a military aircraft, and has advanced sensors and mission systems, including a multi-role radar, high definition cameras and an acoustic system with four times the processing power of the AP-3C Orions.
The government has committed to acquiring 15 P-8A Poseidons, with the AP-3C Orions due for withdrawal in 2018-19. The remaining 11 Poseidons are due to be delivered by March 2020.
"This deployment follows on from Defence’s previous contribution of a P-8A Poseidon maritime patrol aircraft in April, and two AP-3C Orion maritime patrol aircraft in September this year," Minister Pyne said.