TOP HEADLINES

· Russian forces are digging in for the "heaviest of battles" in the strategic southern region of Kherson, a senior Ukrainian official said, as the Kremlin prepares to defend the largest city under its control in Ukraine. READ MORE BELOW

· U.S. President Joe Biden warned Russia against using a nuclear weapon in the conflict with Ukraine, saying such an escalation would be a grave error. Asked by reporters whether he thinks Russia is preparing a "dirty bomb" attack that it would then blame on Ukraine, Biden said: "Russia would be making an incredibly serious mistake were it to use a tactical nuclear weapon." 

· Russia's warning that Ukraine was readying to use a "dirty bomb" fits Moscow's track record of deception, when it "accuses others for what they intend to do themselves," NATO's chief Jens Stoltenberg said. "Russia continues to accuse falsely Ukraine for preparing and making a dirty bomb – that is absurd, because why should Ukraine use a dirty bomb on the territories they want to liberate?" hew said. The UN Security Council met behind closed doors to discuss Moscow's claim. READ MORE BELOW

· Russia's Defense Minister Sergei Shoigu held a phone call with his Indian counterpart and raised Russia's concerns about the possible use of a "dirty bomb" by Ukraine, the ministry said. Shoigu also shared the same concern with his Chinese counterpart.

· Israel's President Isaac Herzog said he was sharing intelligence with the U.S. to prove Iran supplied Russian-operated drones that have reaped destruction in Ukraine, as he urged a tough response. The U.S. and EU have already reached a similar conclusion but Israel has been pushing for tough action against Iran's clerical state, which it views as its biggest threat. 

· U.S. President Joe Biden and UK's new Prime Minister Rishi Sunak agreed to work together to support Ukraine, the White House said. "The leaders agreed on the importance of working together to support Ukraine and hold Russia accountable for its aggression."

· German car maker Mercedes-Benz is expected to sell its Russian assets to a local investor, the Russian ministry of industry and trade said, becoming the latest automaker to exit since Moscow sent troops to Ukraine. "Mercedes-Benz intends to sell its shares in Russian subsidiaries to a local investor," Avtodom, the ministry said in a Telegram statement.

· Ukraine's external financing needs will be around $3 billion a month through 2023 in a best-case scenario, but could rise as high as $5 billion, IMF Managing Director Kristalina Georgieva said.

· The European Commission urged European Union countries and companies to donate more money and equipment to support the energy sector in Ukraine, over a third of which has been destroyed by Russian missile and drone strikes.

IN DETAIL

'Heaviest of battles for Kherson'

Russian forces are digging in for the "heaviest of battles" in the strategic southern region of Kherson, a senior Ukrainian official said, as the Kremlin prepares to defend the largest city under its control in Ukraine.

Russian forces in the region have been driven back in recent weeks and risk being trapped on the west bank of the Dnipro River, where the provincial capital of Kherson has been in Russian hands since the early days of the conflict.

Russian-installed authorities have been encouraging residents to flee to the east bank, but Oleksiy Arestovych, adviser to Ukrainian President Volodymyr Zelenskyy, said there was no sign that Russian forces themselves were preparing to abandon the city.

"With Kherson everything is clear. The Russians are replenishing, strengthening their grouping there," Arestovych said in an online video.

"It means that nobody is preparing to withdraw. On the contrary, the heaviest of battles is going to take place for Kherson."

Kherson is strategically very important as it controls both the only land route to the Crimean peninsula Russia seized in 2014 and the mouth of the Dnipro, the vast river that bisects Ukraine.

Russia's dirty bomb claims: 'Ukraine has nothing to hide'

Russia insisted before the UN Security Council that Ukraine planned to detonate a "dirty bomb" in the war zone, but Western diplomats said Moscow provided no evidence to support the claim.

The Security Council met behind closed doors to discuss Moscow's claim that it believed Ukraine would explode a crude nuclear device in the war zone and blame Russian forces for it.

"We think it's a very serious danger," Russia's deputy UN Ambassador Dimitry Polyanskiy said after the meeting.

"Ukraine has all the reasons to do so because we know that the Zelenskyy regime wants to avoid first of all defeat, secondly wants to involve NATO in a direct clash with Russia," he said.

Such a scheme is "very dangerous but will be profitable for the Zelenskyy regime to remain in power," Polyanskiy said.

"A dirty bomb is not a sophisticated device to be created. Actually, it is a shell with some radioactive waste. And it is very difficult to detect the activities to create these dirty bombs," he added. 

James Kariuki, the British ambassador to the United Nations, rejected Russia's claim.

"We have seen and heard no new evidence during this private meeting," he said, calling the Russian claim "transparently false." 

"Ukraine has been clear, it's got nothing to hide," Kariuki said. "We should be clear this is pure Russian misinformation."

Russian Defense Minister Sergei Shoigu made the initial "dirty bomb" claim on Sunday in calls with NATO counterparts.