LONDON (Reuters), – The West will consider all options in responding to Russia’s chemical weapon use in Ukraine, James Heappey of the British Armed Forces Minister said Tuesday.

British Foreign Secretary Liz Truss stated Monday that Britain is working with partners to confirm reports suggesting Russian forces used chemical agents during an attack on Mariupol in the southeast Ukraine. This city was under siege for nearly seven weeks and thousands of people have been killed.

Heappey stated that there are certain things that go beyond the pale and that chemical weapons would get a response. All options are open for that response. He also said that British intelligence has not been able to confirm the claims.

Heappey was asked on LBC Radio if this could be ruled out. He replied that he had all the options.

Volodymyr Zeleskiy, Ukrainian President, said Monday that Russia may resort to chemical weapons within his country. The West should impose tougher sanctions on Moscow in order to stop any talks of using these weapons.

Heappey stated that if chemical weapons were used, it was a crucial moment for the prime minister of Britain and all heads of state around the globe to think about how they would react to this.

Putin must be very clear with Vladimir Putin, Russian President (Vladimir), that using chemical weapons is unacceptable and that it’s not fair for the West to accept their use.