LIVE: Russia invades Ukraine

Russian president Vladimir Putin has declared war on the nation of Ukraine in eastern Europe, ending weeks of diplomatic stalemate where allies including Aotearoa attempted to de-escalate tensions; "hundreds" of casualties have been reported by the Ukrainian foreign ministry.

A tāne Māori on the border of Russia and Ukraine said families are "being moved away" because of shelling. "It seems like no one knows what’s really going on," he said.

Leaders from Japan, France, Germany, the United States, Australia the UK, Aotearoa and more than 30 members of the NATO alliance have all condemned the Russian invasion of a democratic, sovereign state.

In a televised address early on Thursday (local time) Putin said he had authorised a "special military operation" and claimed Russia had been left with "no choice" but to defend itself against what he said were "threats from modern Ukraine"; he did not identify what the threats were.

In the moments following the 6 am (Moscow) speech explosions were reported in Ukraine's capital city Kyiv, Kramatorsk, Kharkiv, Odessa and Mariupol. It is unclear what the targets were but in recent days the United States has urged Ukrainian president Volodymyr Zelensky to leave the capital.

In Thursday’s speech, Putin threatened countries that would attempt to interfere with his invasion with “consequences they have never seen.”

The president addressed Ukraine forces who had promised to defend their country, telling them to "lay down their arms".

Russia had massed between 150,000 and 190,000 troops along Ukraine’s border in recent months. Diplomats have argued that aggression is “the most significant military mobilization in Europe since World War II.”

Yesterday Putin argued Ukraine was essentially a non-country, saying it should never have been granted independence following the fall of the Soviet Union. NATO allies branded the speech ‘"rambling" and "revisionist history".

The New Zealand government encouraged all Kiwis to leave Ukraine with urgency on February 12.

Yesterday Foreign Affairs minister Nanaia Mahuta (Waikato-Tainui, Ngāti Maniapoto and Ngāti Manu) relayed Aotearoa's opposition to escalating aggression from the Kremlin to the ambassador in Pōneke.

"We repeat our call for Russia to act consistently with its international obligations, and return to diplomatic negotiations as a pathway to resolve this conflict," Mahuta said.

"We have consistently expressed our strong support for Ukraine's territorial integrity and sovereignty, and international diplomatic efforts to de-escalate the crisis to find a peaceful solution.

"A military invasion is an act of aggression and a violation of one of the most basic tenets of international law. New Zealand is ready to take further measures."

Mahuta cautioned the New Zealand government is ready to introduce travel bans, controlled export bans and diplomatic measures in the event of a full invasion of Ukraine.

Since the explosions began, civil defence sirens have sounded across the capital with the Ukrainian president confirming the country's infrastructure and military services on the border are being targeted.

President Zelensky encouraged citizens to stay inside but live video footage shows streams of gridlock traffic attempting to leave the city.

US officials have estimated as many as 50,000 civilians could die in a conflict between the nuclear superpower and Ukraine, a mother on the ground speaking to NBC News told of sending her child to school with a note detailing his blood type, she believed it was not a matter of "if Putin invades, but when".

A surreal UN Security Council meeting was in session when the bombing started. It witnessed one of the most emotional, desperate speeches in its history from the Ukrainian ambassador, Sergiy Kyslytsya.

Since the explosions began, civil defence sirens have sounded across the capital with the Ukrainian president confirming the country's infrastructure and military services on the border are being targeted.

President Zelensky encouraged citizens to stay inside but live video footage shows streams of gridlock traffic attempting to leave the city.

US officials have estimated as many as 50,000 civilians could die in a conflict between the nuclear superpower and Ukraine, a mother on the ground speaking to NBC News told of sending her child to school with a note detailing his blood type, she believed it was not a matter of "if Putin invades, but when".

A surreal UN Security Council meeting was in session when the bombing started. It witnessed one of the most emotional, desperate speeches in its history from the Ukrainian ambassador, Sergiy Kyslytsya.

On Wednesday Washington levelled economic sanctions against Russia which targeted the nation's wealthy class of oligarchs, which diplomats believe have Putin's ear; similarly, Berlin announced should an invasion occur it would refuse to certify Nordstream 2, a new gas pipeline from Russia to Germany.

Oil and gas make up 60% of Russian exports but foreign policy analysts say Putin has been amassing currency reserves to hedge against foreign sanctions, since the 2014 invasion of Crimea in Ukraine's southeast.

Finance Minister Anton Siluanov said last week, while western sanctions against Russian banks could cause market volatility, the country had gathered foreign exchange reserves of $635bn since 2014, the fifth-highest in the world.

Since rallying troops to Ukraine's border Putin has been on a PR offensive with his people; Russian state TV has broadcast footage purporting to be Ukraine shelling Russian forces, something Ukraine and western allies have vehemently denied, arguing Putin was using the videos for so-called 'false flag' operations to stoke nationalist loyalties and appetite for war.

Putin has previously said the Kremlin's issue with Ukraine is its desire to join NATO, the North Atlantic Treaty Organisation alliance between 28 European and Eurasian countries and North America.

NATO was established in 1947 for allies to hedge against assaults from Germany or the then Soviet Union; the treaty states an attack on one country is an attack on all, which should be met with a united military response.

Putin demanded NATO allies say Ukraine would be excluded from admission to the alliance in January; allies said exclusion would violate the terms of the treaty but that Ukraine was not being considered for membership.

Ukrainian allies including the United States, EU countries and the UK have all said they won't provide troop support for Ukraine, but some have provided military hardware to Kyiv in recent weeks.

Additional reporting: James Perry