UK Warns 'All Options on the Table' Amid Claims of Chemical Weapons Use in Mariupol

Ukrainian President Volodymyr Zelensky earlier sought to remind Western leaders, including US President Joe Biden, of their threats that the alleged use of chemical weapons by Russia would be a "red line" to which they would respond "in kind".

The UK has warned "all possible options" are being considered after unsubstantiated claims by Ukrainian forces that chemical weapons were used against neo-Nazis holding out in the city of Mariupol.

British government ministers seized on Ukraine's allegations on Monday night to call for even more aggressive action against Russia.

"Let's be clear, if they are used at all then President Putin should know that all possible options are on the table in terms of how the West might respond", Armed Forces Minister James Heappey told Sky News on Monday morning.

Heappey said it was "Not for any government minister from an individual country to pledge NATO involvement" by itself, but but added that it was "perfectly possible that a response to chemical weapons use could happen without NATO involvement."

"'All options on the table’ is meant as a deterrent to President Putin," the minister said.

'What do we know about an alleged chemical attack in Mariupol?' - #KayBurley

James Heappey MP says they have not been able to verify the reports yet, but the UK is working to verify the details.https://t.co/xV5qMhVxX7

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— Sky News (@SkyNews) April 12, 2022

But Heappey admitted that the government had no evidence of what, if any, chemical agent could have been used, saying that tear gas used by riot police was a possibility.

.@KayBurley:'On the alleged attack, if it is proven, what happens next?'

James Heappey MP says "there are weapons that simply should not be used and if they are used, people will be held to account."

Latest on Ukraine: https://t.co/gU2VXsx8ui

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— Sky News (@SkyNews) April 12, 2022

"We are working urgently with partners to verify details", Foreign Secretary Liz Truss tweeted late on Monday night. "Any use of such weapons would be a callous escalation in this conflict and we will hold Putin and his regime to account".

The neo-Nazi Azov Battalion claimed on Monday that three of its gunmen in the huge Azovstal steel works surrounded by DPR and Russian forces had been injured by "a poisonous substance".

And on his nightly television broadcast on Monday, Ukrainian President Volodymyr Zelensky sought to "remind" Western leaders of previous threats to retaliate against Russia if it crossed the "red line" of using chemical weapons.

"I would like to remind world leaders that the possible use of chemical weapons by the Russian military has already been discussed", Zelensky said. "And already at that time it meant that it was necessary to react to the Russian aggression much harsher and faster".

A spokesman for the Donetsk People's Republic's (DPR) militia denied the allegations.

"No chemical weapons have been used by the DPR forces in Mariupol", Eduard Basurin said on Tuesday.

Zelensky has repeatedly used accusations against Russian forces to pressure NATO to send more arms into the war zone or even attempt to impose a "no-fly zone" — which would, according to observers, bring forces of the rival nuclear powers into direct conflict.

On a visit to neighbouring NATO member Poland last month, US President Joe Biden said America would respond "in kind" to any alleged Russian chemical warfare attack — and said Russian President Vladimir Putin "cannot be allowed to remain in power". His unscripted remarks caused alarm across the West and were quickly rowed back by the White House and State Department.

Russia destroyed the last of its Cold War-era chemical weapons stockpile in 2017, as verified by the Organisation for the Prohibition of Chemical Weapons (OPCW).

Moscow earlier announced that Kiev was planning "false flag" chemical contamination incidents which it would try to blame on Russia — as when Ukrainian forces blew up a tank containing hydrochloric acid in Rubezhnoye in the fellow breakaway Lugansk People's Republic a week ago.

Also on Tuesday, Russian Ministry of Defence spokesman Major-General Igor Konashenkov said an attempted overnight break-out by Ukrainian forces surrounded in another factory in the city had failed disastrously.

"On 11 April, in Mariupol, the remnants of Ukrainian troops surrounded on the territory of the 'Ilyich' plant made an unsuccessful attempt to break out of the city at night", Konashenkov said. "A group of up to 100 Ukrainian soldiers in armoured vehicles tried to fight their way out of the plant and leave the city in a northern direction".

"Air and artillery strikes foiled this breakthrough attempt", the Russian general added, saying three Ukrainian tanks, five infantry fighting vehicles, and seven light vehicles were destroyed and up to 50 troops killed, while "another 42 Ukrainian servicemen voluntarily laid down their arms and surrendered".

On Monday, DPR leader Denis Pushilin said Mariupol's civil port in the west of the city had been finally cleared of hostile militants.

But Basurin estimated there could be between 3,500 and 4,000 Ukrainian Army troops, neo-Nazi Azov extremists, and Western mercenaries and military advisers still holed up in the sprawling Azovstal complex.