Prime Minister Jacinda Ardern says New Zealand is not in a position to intervene as Samoa's two major political parties continue to battle it out for power.
Samoa was plunged into a constitutional crisis yesterday when the woman who won last month's election was locked out of Parliament as the previous leader refused to cede power.
Prime Minister-elect Fiame Naomi Mata'afa and her supporters showed up to form a new Government, but were not allowed inside Parliament.
Instead, she and her Fast Party took oaths and appointed ministers in a ceremony held under a tent — actions her opponents claim are illegal.
The fast-moving events marked the latest twist in a bitter power struggle that has been playing out in the small Pacific nation since it elected its first female leader.
Ardern said New Zealand encouraged "all parties and political leaders" to uphold the election outcome and the decisions of institutions including the judiciary, and the rule of law.
However, she said New Zealand was not in a position to be playing "any interventionist role".
Ardern said despite the fact there was a "changeable" political situation in Samoa, reports were that the situation was calm late yesterday, in line with calls from political and faith community leaders.
But tensions do remain high following the outdoor ceremony, conducted after Fast deputy leader Laauli Leautea Schmidt confronted the deputy assistant police commissioner on why Parliament's doors were locked and asked his forces to uphold the rule of law.
He was told police were not taking sides and were only there to offer security.
The ceremony then involved a prayer and later loud applause from supporters as Fiame took an oath to become the country's new Prime Minister.
She went on to tell them: "There will be a time when we will meet again, inside that House. Let us leave it to the law."
The ceremony came after the nation's Supreme Court ordered the Parliament to convene. The constitution requires that lawmakers meet within 45 days of an election — yesterday marking the final day by that count.
Tuilaepa Sailele Malielegaoi, who leads the minority party after the April 9 election, yesterday held a press conference claiming his Government remained in charge.
"There is only one Government in Samoa, even if we are just the custodian Government. We remain in this role and operate business as usual."
Tuilaepa then held a second news conference to say that action would be taken against party members. "This is treason, and the highest form of illegal conduct," he said.
The Attorney General's office also put out a statement last night saying the ceremony swearing in a new Government on the footsteps of Parliament was unconstitutional and all persons involved were subject to civil and criminal prosecution under the law.
Tuilaepa, who has been in power for 22 years, said only the Head of State can call Parliament meetings and swear people in. "None of what they did is legitimate. The Devil has won and taken over them.
"That was a joke, a joke. Oh my, where have we ever seen a Speaker sworn in, in a tent? Shameful."
Tuilaepa said the tent ceremony made the people of Samoa look like fools.
Victoria University of Wellington's Dr Iati Iati said two questions remained after yesterday's developments: How legitimate was the swearing-in ceremony and how will Tuilaepa's party respond today?
"Obviously there was no head of state, no chief justice around [at the ceremony], which you would expect at something like this. He wasn't sure if former Attorney General Taulapapa Brenda Heather-Latu, who acted as the clerk of the swearing ceremony, had the power to do so.
"Obviously, as a lawyer, she must've read something in the constitution that she has interpreted to mean she has the authority to do this. In time, we will find out if that really is the case or not.
"I thought both sides were handling the situation in a very measured way. In particular, I thought Fiame ... was quite composed, at the same time quite stern ... peaceful in the way she was responding to the events as they unfolded."
But he was surprised by the swearing-in ceremony because it didn't seem to be in character with what Fiame had done until now.
"I think this has ratcheted things up a little bit and could bring what are tensions that we've seen in the country ... could possibly bring them to boiling point. It all depends on how the HRP Party respond [today]."
Last month's election initially ended in a 25-25 tie between Fast and HRPP, with one independent candidate.
The independent candidate chose to go with Fiame, but meanwhile, the electoral commissioner appointed another HRPP candidate, saying that was required to conform to gender quotas. That made it 26-26.
The Head of State then stepped in to announce fresh elections to break the tie. Those elections in the nation of 200,000 were scheduled to be held last week.
But Fiame's party appealed, and the Supreme Court ruled against both the appointed candidate and the plans for the new elections, restoring the Fast Party to a 26-25 majority.
Fiame's election win was seen as a milestone not only for Samoa, which is conservative and Christian, but also for the South Pacific, which has had few female leaders.
An advocate for women's equality, Fiame, who was born in 1957, broke new ground during her campaign by going on the road and robustly criticising the incumbent.
She is the daughter of the first Prime Minister, the late Mata'afa Fiame Faumuina Mulinu'u II, and was the former Deputy Prime Minister before joining Fast.
RNZ journalist Jamie Tahana, who has been covering the story, said it was hard to know where the standoff will end up.
"Ultimately the judiciary — already under immense pressure, which it has so far held up to — is likely to be put to the test again. But we've already seen a propensity for the judiciary to be ignored in the last few days," Tahana said.
"Right now, with the sun set in Samoa, there seems to be more questions than answers.
"No one knows what will happen, when this will end, or for how long this will drag out."
- AP, RNZ and agencies