US President Joe Biden has agreed to provide Ukraine with advanced rocket systems that can strike with precision at long-range Russian targets as part of a $US700 million ($974 million) weapons package expected to be unveiled on Wednesday.
The latest US pledge of weapons for Ukraine — on top of billions of dollars worth of equipment already provided including anti-aircraft missiles and drones — came as Russia pressed its assault to seize the eastern Donbas region
Ukraine has also identified more than 600 Russian war crime suspects and has started prosecuting around 80 of them.
In a New York Times op-ed published on Tuesday, Mr Biden said Russia's invasion of Ukraine would end through diplomacy but the United States must provide significant weapons and ammunition to give Ukraine the highest leverage at the negotiating table.
"That's why I've decided that we will provide the Ukrainians with more advanced rocket systems and munitions that will enable them to more precisely strike key targets on the battlefield in Ukraine," he wrote.
A senior Biden administration official said the weaponry provided would include the M142 High Mobility Artillery Rocket System (HIMARS), which Ukraine's armed forces' chief said a month ago was "crucial" to counter Russian missile attacks.
Addressing concerns the provision of such weapons could draw the United States into a direct conflict with Russia, senior administration officials said Kyiv gave "assurances" the missiles would not be used to strike inside Russia.
"These systems will be used by the Ukrainians to repel Russian advances on Ukrainian territory, but they will not be used on targets in Russian territory," the US official told reporters.
The package also includes ammunition, counter-fire radars, a number of air surveillance radars, additional Javelin anti-tank missiles, as well as anti-armour weapons, officials said.
Ukrainian officials have been asking allies for longer-range missile systems that can fire a barrage of rockets hundreds of miles away, in the hopes of turning the tide in the three-month-long war.
Mr Biden on Tuesday told reporters that "we're not going to send to Ukraine rocket systems that strike into Russia".
He did not rule out providing any specific weapons system, but instead appeared to be placing conditions on how they could be used.
Mr Biden wants to help Ukraine defend itself but has been opposed to providing weapons that Ukraine could use to attack Russia.
Russia on Wednesday said that the US decision to supply advanced rocket systems and munitions to Ukraine was extremely negative and would increase the risk of a direct confrontation.
Russian Deputy Foreign Minister Sergei Ryabkov told state news agency RIA Novosti that Moscow views US military aid to Ukraine "extremely negatively".
Ukraine identifies 600 war crime suspects
Ukraine prosecutor-general Iryna Venediktova told a news conference in The Hague on Tuesday that her country's list of war crimes suspects included "top military, politicians and propaganda agents of Russia".
Ms Venediktova said Estonia, Latvia and Slovakia had decided to join an international investigation team in Ukraine — which was originally formed by Ukraine, Lithuania and Poland in March — to enable the exchange of information and investigation into suspected war crimes and crimes against humanity.
They are working with the International Criminal Court (ICC), which launched its own investigation into possible war crimes in Ukraine in early March.
ICC prosecutor Karim Khan — whose office deployed a team of 42 investigators, forensic experts and support personnel to Ukraine — said the ICC was "working toward opening an office in Kyiv" to support the investigations.
Russia has denied targeting civilians nor any involvement in war crimes while it carries out what it calls a "special military operation" in Ukraine.
Air strike hits Sievierodonetsk chemical plant
Meanwhile, Ukrainian officials said a Russian air strike had hit a chemical plant in the eastern city of Sievierodonetsk.
The local governor, Serhiy Gaidai, said Russian missiles had struck a tank full of nitric acid.
He urged local residents not to leave their bomb shelters, due to a high risk of inhaling toxic fumes.
The Luhansk People's Republic's police force said Ukraine's forces had damaged the plant.
Anton Gerashchenko — an adviser to Kyiv’s Ministry of Internal Affairs — shared a message on Telegram and Twitter, alongside an image of large, pink clouds of smoke rising above buildings.
Mr Gaidai said nearly all critical infrastructure in Sievierodonetsk had been destroyed and 60 per cent of residential property damaged beyond repair.
"Most of Sievierodonetsk is under the control of the Russians. The town is not surrounded and the prerequisites for it to be are not in place," he said.
Russian shelling had made it impossible to deliver aid or evacuate people, he added.
A pro-Moscow separatist leader said that fighting was raging in the city but that Russian proxies had advanced slower than expected to "maintain the city's infrastructure" and exercise caution around its chemical factories.
"We can say already that a third of Sievierodonetsk is already under our control," Russia's TASS state news agency quoted Leonid Pasechnik, the leader of the pro-Moscow Luhansk People's Republic, as saying.
'Hurling men and munitions'
Russian President Vladimir Putin "is now hurling men and munitions" at Sievierodonetsk, "as if taking it would win the war for the Kremlin. He is wrong," the Washington-based Institute for the Study of War wrote this week.
Thousands of residents remain trapped in the city.
Russian forces were advancing towards the centre of the city, but slowly, Mr Gaidai said.
Russia's advance could force Ukrainian troops to retreat across the river to Lysychansk, he added.
Jan Egeland, secretary-general of the Norwegian Refugee Council aid agency, which had long operated out of Sievierodonetsk, said he was "horrified" by its destruction.
Up to 12,000 civilians remain caught in crossfire, without sufficient access to water, food, medicine or electricity, Mr Egeland said.
"The near-constant bombardment is forcing civilians to seek refuge in bomb shelters and basements, with only few precious opportunities for those trying to escape," he said.
There have been few reports of major shifts elsewhere on the battlefield.
In the south, Ukraine claimed to have pushed back Russian forces to the border of Russian-held Kherson province.
ABC/wires
