Joe Biden warns of World War Three if Nato and Russia clash in a direct conflict

ITV News Correspondent Dan Rivers reports on the ways in which Russia has widened its offensive in Ukraine and what it means for desperate residents still trapped in targeted areas

Joe Biden has warned that a direct conflict between Russia and Nato would amount to "World War Three," as he resisted the idea of a no-fly zone to protect Ukrainians from Moscow's forces.

The US President said that he would defend "every inch of Nato territory" but that a direct war against Russian troops in Ukraine would not be fought.

"A direct confrontation between Nato and Russia is World War III. And something we must strive to prevent," he tweeted on Friday night.

Mr Biden told Democrats that the US would defend Nato members bordering Russia, which include Poland, Estonia and Latvia.

But he said: "The idea that we're gonna send in offensive equipment and have planes and tanks and trains going in with American pilots and American crews... that's called World War Three, OK?"

The remarks come after the president vetoed Poland's offer to transfer its MiG-29 fighter jets to an American base in Germany as a way to replenish Ukraine's air force in its battle against Russian forces.

The Pentagon, which has also opposed a no-fly zone above the Ukraine amid fears it could escalate conflict, says it would resist any plan for Nato nations to provide fighter jets to Ukraine, calling the move “high-risk”.

Diplomatic talks took a bizarre turn on Friday after Russia made unsubstantiated and false claims that the US has been helping Ukraine to develop a biological weapons programme.

Vasily Nebenzya, Russia's ambassador to the UN, said that Russia had proof of a network of "at least 30" biological research labs aimed at strengthening several "lethal diseases".

The claims, which are completely baseless and have been made without evidence, are denied by both Washington and Kyiv.

Nebenzya claimed during a meeting of the UN Security Council on Friday that: "Our Ministry of Defence - Russian Ministry of Defence - now has documents which confirms that on the territory of Ukraine there was a network consisting of at least 30 biological laboratories in which very dangerous biological experiments were being conducted."

"This work is being done and funded and supervised by the Defence Threat Reduction Agency of the United States," Nebenzya claimed during the session, which was convened at Russia's request.

Ukraine's ambassador to the US Oksana Markarova has spoken to ITV News' Rageh Omaar about the unfolding crisis in Ukraine

Russia also claimed that the Ukraine had sought to use migratory birds to spread pathogens, raising concerns the accusations could be used to give cover for a potential Russian use of biological weapons.

"Our military became aware of the details of the project UP4 which was being conducted in laboratories of Kyiv, Kharkiv and Odesa. The goal is to study the possibility of spreading, particularly dangerous infections, using migratory birds," the Russian ambassador said.

“We call upon you to think about a very real biological danger to the people in European countries, which can result from an uncontrolled spread of bio agents from Ukraine.” 

What is the strategy behind Russia's outlandish claims? ITV News Correspondent Robert Moore reports from Washington

However, the US hit back hard at the claims, accusing Russia of "lying and spreading disinformation” as part of a potential false-flag operation by Moscow to justify a biological or chemical weapons attack in Ukraine.

A false flag event is when a military or political action takes place by one side with the aim of blaming it on their opponent.

“The intent behind these lies seems clear, and is deeply troubling,” US Ambassador to the UN Linda Thomas-Greenfield said.

“We believe Russia could use chemical or biological agents for assassinations, as part of a staged or false-flag incident, or to support tactical military operations.”

Ms Thomas-Greenfield added that Ukraine doesn’t have a biological weapons programme or biological weapons laboratories supported by the US as Russia claimed.

The claims follow a chilling warning from Ukraine’s Defence Intelligence.

It said: "The Russian-controlled Chernobyl nuclear power plant plans to create a man-made catastrophe, for which the occupiers will try to shift responsibility to Ukraine."

Ukraine's state-run nuclear company Energoatom previously warned that radioactive substances could be released from the plant because it cannot cool spent nuclear fuel, after its power connection was severed.

But on Friday, Ukraine told the International Atomic Energy Agency (IAEA) that technicians had repaired one section of the damaged power lines at the plant, which was taken by Russian forces early in the invasion.

The IAEA said that repair efforts would continue despite “the difficult situation” outside the plant, which was the site of the 1986 nuclear disaster.

The developments come after a day in which Moscow broadened its targets in Ukraine and targeted cities not previously hit.

Is Russia expanding the war into the West? ITV News Europe Editor James Mates reports live from Kyiv

• Where in the Ukraine is now being targeted by Russia?

Russia's fresh round of attacks were launched in western cities far from Moscow's main targets and could indicate a new direction of the war.

Three Russian airstrikes also hit the eastern industrial city of Dnipro on Friday, killing at least one person, according to Interior Ministry adviser Anton Heraschenko.

It is the first time the city has come under attack during the invasion.

The Russian strikes hit near a kindergarten and apartment buildings, while one sparked a fire at a shoe factory.

So far, the Russians have made the biggest advances on cities in the east and south- including in Mariupol, the heavily bombarded seaport where food and water supplies are running dangerously low.

On Friday, Putin’s forces continued to launch airstrikes in urban areas such as Kyiv and Kharkiv.

• How close are Russian troops to Kyiv?

Russian forces were pushing toward Kyiv, the strategically vital Ukrainian capital, from the northwest and east.

However, they have been repelled from the northern city of Chernihiv, as Ukrainian fighters regained control of the village of Baklanova Muraviika, the general staff of Ukraine's armed forces said in a statement. A convoy seen in satellite imagery from Maxar Technologies showed a 40-mile line of vehicles, tanks and artillery had been broken up and redeployed, the company said.

Photos indicated that its troops, long stalled in a convoy outside the capital Kyiv, were manoeuvring in an attempt to encircle the city.

Armoured units were seen in towns near Antonov Airport - about 35 miles north-west of Kyiv, with some of the vehicles reportedly having moved into forests.

The convoy had massed outside the city early last week, but its advance appeared to stall as reports of food and fuel shortages circulated.

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