The trip was planned before Poland took the United States by surprise on Tuesday by offering to send its Mig-29 jets to Ukraine via a US air base.

On February 24, Russia invaded Ukraine and seized the defunct Chernobyl plant, site of a 1986 disaster that killed hundreds and spread radioactive contamination west across Europe.

There's no consensus on what the letter actually signifies, but almost two weeks into Russia's military incursion into Ukraine it has become synonymous with the Russian army.

The Vienna-based UN body said Ukrainian authorities reported an attack took place on Sunday, adding that no increase in radiation levels had been reported at the site.

The attack took place two days after Russia attacked the Zaporizhzhya Nuclear Power Plant, Europe's largest nuclear power station in southern Ukraine, having already captured the Chernobyl nuclear power complex in the north.

Amid tight security, Blinken and Kuleba held talks in a tent on the border where refugees, mostly women and children, were also crossing with their belongings in rolling luggage and backpacks.

"We know for sure that Ukrainian combat aircraft have flown to Romania and other neighbouring countries," defence ministry spokesman Igor Konashenkov said in a video briefing. 

According to Orange, nearly 9,000 subscribers of a satellite internet service provided by its subsidiary Nordnet in France are without internet following a "cyber event" on February 24 at Viasat, a US satellite operator of which it is a client. 

Ukrainian leader Volodymyr Zelensky has pleaded with the West to support a no-fly zone as his besieged country continues to resist Moscow's invasion, now in its second week. 

Moscow and Kyiv traded blame over a failed ceasefire plan that would have let civilians flee Mariupol and Volnovakha, two southern cities besieged by Russian forces. Another round of talks was tentatively planned for Monday as Ukrainians who could escape spilled into neighboring Poland, Romania, Slovakia and elsewhere.

Prime Minister Naftali Bennett's sit-down with Putin was the first by a foreign leader since the day Russian forces invaded Ukraine last week, and came after Kyiv had asked Israel to launch a dialogue with Moscow. 

Two members of security staff were injured when the projectile hit overnight after the Ukrainian authorities reported a battle with Russian troops near Europe's biggest power plant, which is operating at just a small fraction of its capacity with one of its six units still running.

The Ukrainian nuclear regulator said that the fire had been extinguished and no radiation leak had been detected, with site staff still able to work at the Zaporizhzhia site.

"No country other than Russia has ever fired on nuclear power units," he said in a video message released by his office. "This is the first time in our history. In the history of mankind. The terrorist state now resorted to nuclear terror."

"If it blows up, it will be 10 times larger than Chornobyl!" the minister said, referring to one of the world's worst nuclear disasters that occurred in 1986 at the Chernobyl plant in Ukraine, then part of the Soviet Union.

"IAEA Director General @RafaelMGrossi speaks with #Ukraine PM Denys Shmygal and with Ukrainian nuclear regulator and operator about serious situation at #Zaporizhzhia Nuclear Power Plant, appeals for halt of use of force and warns of severe danger if reactors hit," the International Atomic Energy Agency tweeted.

Indonesia's envoy to the United Nations said that the international community must go beyond condemnation and start “restoring trust and confidence”, as analysts predict the potential effects of the Ukraine crisis.

But the failures of the first days, including vastly underestimating the Ukrainians' willingness to fight back, could lead to a frustrated Moscow deciding to unleash all its power and indiscriminately destroying large swathes of Ukraine, they said.

Moscow's offensive marks a turning point for the whole world.

After more than two days of extraordinary debate, which saw the Ukrainian ambassador accuse Russia of genocide, 141 out of 193 United Nations member states voted for the non-binding resolution. 

In all, 874,026 people have fled across the country's borders, according to the website of UNHCR, the UN refugee agency.

The attack on Tuesday night damaged Kyiv's main television mast at Babi Yar, the scene of World War II's biggest slaughter of the city's Jews and a place of memorial and pilgrimage.

This week, he and his family had to flee again -- this time to Poland to the sounds of Russian bombs.

But forces of Belarus, a close ally of Russia, would not be taking part in the attack on Ukraine, he added.

Indonesia stood by its pacifist stance on the Russian invasion of Ukraine at an emergency special session of the United Nations General Assembly this week.

The shelling of Kharkiv has destroyed a school and, according to its mayor, killed at least 11 civilians. 

The troops will train in long-distance movements of military units, among other tasks, the district command said.

Rafael Grossi, director general of the International Atomic Energy Agency, said he had received reports that the soldiers were close to the Zaporizhzhia station in eastern Ukraine.

Ukraine has said its goal for the talks is an immediate ceasefire and the withdrawal of Russian forces from Ukraine. Russia has been cagier, with the Kremlin declining to comment on Moscow's aim in negotiations.

In October 1962, at the heart of the Cold War, a 13-day showdown between Soviet leader Nikita Khrushchev and US president John F. Kennedy leads to fears of nuclear war.