Foreign Affairs Minister Nanaia Mahuta has condemned a coup by Myanmar's military following the arrest of leader Aung San Suu Kyi.
Aung San Suu Kyi and other political leaders were arrested in the early hours.
Hours after the arrests of Aung San Suu Kyi and other political leaders, military TV confirmed a state of emergency had been declared for one year.
The coup comes after tensions rose between the civilian government and the military following a disputed election.
Myanmar, also known as Burma, was ruled by the military until democratic reforms began in 2011.
The military said on Monday it was handing power to commander-in-chief Min Aung Hlaing. Soldiers are on the streets of the capital, Nay Pyi Taw, and the main city, Yangon.
In November's election, Suu Kyi's National League for Democracy (NLD) won enough seats to form a government. The army said the vote was fraudulent.
Foreign Affairs Minister Nanaia Mahuta this evening said an election had taken place and that the democractic will of the people must be respected.
Earlier in a statement, a Ministry of Foreign Affairs spokesperson said New Zealand was "deeply troubled" by the situation and called for the immediate release of the political prisoners.
"We call for the swift release of all of those detained, and for any issues to be resolved through peaceful dialogue," the statement said.
"New Zealand officials are closely monitoring the situation."
There are currently 58 New Zealanders registered on SafeTravel as being in Myanmar.
"New Zealanders in Myanmar are advised to avoid any unnecessary travel for the time being and to monitor media reporting for more information", the MFAT statement said.
New Zealand does not currently have any diplomatic staff in Myanmar with the embassy temporally closed due to the Covid-19 pandemic.
The BBC's South East Asia correspondent Jonathan Head said the coup appeared to be a clear violation of the constitution drafted by the military more than a decade ago, and which it promised to honour only on Saturday.
Detaining political leaders like Suu Kyi was a provocative and very risky move, one which may well be strongly opposed, Head said.
Telephone and internet lines in Naypyitaw have been cut, the BBC's Burmese Service reported.
Soldiers also visited the homes of chief ministers in several regions and took them away, family members said.
US condemns coup
The United States has condemned the coup, saying Washington "opposes any attempt to alter the outcome of recent elections or impede Myanmar's democratic transition".
US Secretary of State Antony Blinken called for the release of all government officials and civil society leaders and said the US "stands with the people of Burma in their aspirations for democracy, freedom, peace, and development. The military must reverse these actions immediately".
In Australia, Foreign Affairs Minister Marise Payne said "we call on the military to respect the rule of law, to resolve disputes through lawful mechanisms and to release immediately all civilian leaders and other who have been detained unlawfully".
John Sifton of Human Rights Watch said: "The military junta that ruled Myanmar for decades never really stepped away from power in the first place.
"They never really submitted to civilian authority in the first place, so today's events in some sense are merely revealing a political reality that already existed," Sifton said.
"The doors just opened to a very different future," Thant Myint-U, Yangon-based historian and author described the outlook.
"I have a sinking feeling that no one will really be able to control what comes next.
"And remember Myanmar's a country awash in weapons, with deep divisions across ethnic and religious lines, where millions can barely feed themselves."
Who is Aung San Suu Kyi?
Aung San Suu Kyi is the daughter of Myanmar's independence hero, General Aung San. He was assassinated when she was only two years old, just before Myanmar gained independence from British colonial rule in 1948.
Suu Kyi was once seen as a beacon for human rights - a principled activist who gave up her freedom to challenge the ruthless army generals who ruled Myanmar for decades.
In 1991, she was awarded the Nobel Peace Prize, while still under house arrest, and hailed as "an outstanding example of the power of the powerless".
Suu Kyi spent nearly 15 years in detention between 1989 and 2010.
In November 2015 she led the National League for Democracy (NLD) to a landslide victory in Myanmar's first openly contested election for 25 years.
The Myanmar constitution forbids her from becoming president because she has children who are foreign nationals. But Suu Kyi, now 75, is widely seen as de facto leader.
But since becoming Myanmar's state counsellor, her leadership has been defined by the treatment of the country's mostly Muslim Rohingya minority.
In 2017 hundreds of thousands of Rohingya fled to neighbouring Bangladesh due to an army crackdown sparked by deadly attacks on police stations in Rakhine state.
Suu Kyi's former international supporters accused her of doing nothing to stop rape, murder and possible genocide by refusing to condemn the still powerful military or acknowledge accounts of atrocities.
A few initially argued that she was a pragmatic politician, trying to govern a multi-ethnic country with a complex history.
But her personal defence of the army's actions at the International Court of Justice hearing in 2019 in the Hague was seen as a new turning point that obliterated what little remained of her international reputation.
At home, however, "the Lady", as Suu Kyi is known, remains wildly popular among the Buddhist majority who hold little sympathy for the Rohingya.
-BBC/Reuters/RNZ