Special Military Operation threatens to go mushroom-shaped as talk of a dirty bomb starts floating around

WASHINGTON/KYIV, Oct 24 (Reuters) - The United States warned on Monday there would be severe consequences if Russia used a nuclear weapon in Ukraine, as Western countries accused Moscow of plotting to escalate the war on the pretext that Kyiv was planning to deploy a "dirty bomb" laced with nuclear material.

With Ukrainian forces advancing into Russian-occupied Kherson province, top Russian officials phoned Western counterparts on Sunday and Monday to tell them of Moscow's suspicions. Russia plans to raise the issue at the U.N. Security Council on Tuesday, diplomats said.

The foreign ministers of France, Britain and the United States rejected the allegations and reaffirmed their support for Ukraine.

"Our countries made clear that we all reject Russia’s transparently false allegations that Ukraine is preparing to use a dirty bomb on its own territory," they said in a joint statement. "The world would see through any attempt to use this allegation as a pretext for escalation."

Later, the United States issued a warning to Moscow.

"We've been very clear with the Russians ... about the severe consequences that would result from nuclear use," State Department spokesman Ned Price said.

"There would be consequences for Russia whether it uses a dirty bomb or a nuclear bomb."

Russian military Chief of General Staff Valery Gerasimov spoke to the chairman of the U.S. Joint Chiefs of Staff, Mark Milley, on Monday, Russia's RIA news agency reported. The call was the first between the top generals since May, a U.S. military official said, and came eight months to the day since Russia invaded Ukraine.

U.S. officials said there was no indication Moscow had made the decision to use nuclear weapons.

"We continue to see nothing in the way of preparations by the Russian side for the use of nuclear weapons," White House national security spokesman John Kirby told reporters. "And nothing with respect to the potential use for a dirty bomb at this point."

Russia's defence ministry said the aim of a "dirty bomb" attack by Ukraine would be to blame Russia for the resulting radioactive contamination. The ministry has begun preparing for such a scenario, it said, readying forces and resources "to perform tasks in conditions of radioactive contamination."

Ukrainian President Volodymyr Zelenskiy had said the Russian accusation was a sign Moscow was planning such an attack itself and would blame Ukraine.

"If Russia calls and says that Ukraine is allegedly preparing something, it means one thing: Russia has already prepared all this," Zelenskiy said in an overnight address.

The U.N. nuclear watchdog said on Monday it was preparing to send inspectors in the coming days to two Ukrainian sites at Kyiv's request, in an apparent reaction to the Russian "dirty bomb" claims.

A local man throws debris out of a broken window in a residential building heavily damaged by a Russian missile attack in Mykolaiv, Ukraine October 23, 2022. REUTERS/Valentyn Ogirenko

EVACUATION

Russia has ordered civilians to evacuate territory it controls on the western bank of the Dnipro River, where Ukrainian forces have been advancing this month shortly after Moscow claimed to have annexed the area.

A Russian defeat there would be one of Moscow's biggest setbacks yet.

Kherson's regional capital is the only big city Russia has captured intact since its Feb. 24 invasion, and its only foothold on the west bank of the Dnipro, which bisects Ukraine. The province controls the gateway to Crimea, the peninsula Russia seized and claimed to annex in 2014.

The Russian-installed authorities in Kherson announced on Monday that men who stay behind would have the option of joining a military self-defence unit. Kyiv accuses Russia of press-ganging men in occupied areas into military formations, a war crime under the Geneva Conventions.

Kyrylo Budanov, Ukraine's military spy chief, said Russian forces were preparing to defend Kherson city, not retreat.

"They are creating the illusion that all is lost. Yet at the same time they are moving new military units in and preparing to defend the streets of Kherson," he told the Ukrainska Pravda online media outlet.

The General Staff of the Ukrainian Armed Forces said on Facebook that Russian missile and air raids damaged infrastructure in heavily contested areas of the Donetsk region in the east and in areas of the Kharkiv region in the northeast.

About 10 towns came under attack in the Zaporizhzhia region of central Ukraine, it said, as did eight towns on the southern front - where Ukrainian forces are engaged in a counter-offensive in Kherson.

Since Russia's forces suffered major battlefield defeats in September, President Vladimir Putin has escalated the war, calling up hundreds of thousands of reservists, announcing the annexation of occupied territory and repeatedly threatening to use nuclear weapons to defend Russian land.

This month, Russia started a new campaign using long-range cruise missiles and Iranian-made drones to attack Ukraine's energy infrastructure before winter sets in.

Russian state television is filled with talk shows featuring pundits who are openly cheering attacks on Ukrainian civil infrastructure.

On Monday, Russian state TV presenter Anton Krasovsky apologised for remarks in which he called for Ukrainian children to be drowned in rivers and burned alive in huts with the doors nailed shut. He also joked that Ukrainian grandmothers were saving their funeral funds to pay Russian soldiers to r*pe them.

Krasovsky was suspended from Russia's state-funded international channel RT, and Russia's Investigative Committee said it had ordered a report into his "sharp comments".