The Australian government has voiced concern at Vanuatu's decision to expel all Australian Federal Police from the country.
The decision is in response to Australia's treatment of Vanuatu's Prime Minister Sato Kilman last month when he travelled through Sydney.
While in transit with Mr Kilman, one of his advisors was arrested for alleged international tax fraud.
The Prime Minister likened the incident to kidnapping, and called it a breach of protocol.
Vanuatu's foreign minister, Alfred Carlot, who issued the expulsion notice, says the action was in response to the way Mr Kilman was treated and not linked to the advisor's arrest.
A spokesperson for Australia's Department of Foreign Affairs and Trade says they regret that it was necessary to make the arrest.
He says all measures were taken to ensure it was respectful of Prime Minister Kilman's position and the need to protect his dignity.
The Australian foreign minister, Bob Carr, has urged the Vanuatu government to reconsider its plans, saying the people of Vanuatu would be losing a valuable source of aid if Australian police are forced to leave.