The UK has sanctioned a Russian public official for the “forced transfer and adoption of Ukrainian children”, the foreign secretary Liz Truss said.

The latest wave of sanctions in response to Russia's invasion of Ukraine also targets four colonels from the 64th Separate Motorised Rifle Brigade, a unit known to have killed, raped and tortured civilians in Bucha, and the head of the Russian Orthodox Church, Patriarch Kirill, who Ms Truss said had “repeatedly abused his position to justify the war”.

Maria Lvova-Belova, Russia’s children's rights commissioner, was targeted as she had been accused of enabling 2,000 vulnerable children to be violently taken from Ukraine’s Donbas region for adoption in Russia.

Each individual had their assets frozen, preventing them from dealing with British banks or businesses, and has been banned from travelling to the UK.

Announcing the measures in the House of Commons on Thursday, Ms Truss said: “Today we are targeting the enablers and perpetrators of Putin’s war who have brought untold suffering to Ukraine, including the forced transfer and adoption of children.

“We will not tire of defending freedom and democracy, and keeping up the pressure on Putin, until Ukraine succeeds.”

Others sanctioned include Sergey Savostyanov, deputy leader of the Moscow city assembly and Alexey Isaykin, president and board member of Volga-Dnepr Group, a Russian transport company tasked by Vladimir Putin to facilitate aerial goods transport.

Members of the Salvation Committee for Peace and Order, an organisation collaborating with the Russian army to support the occupation of the Kherson Oblast, were hit too.

Beyond Ukraine, the measures have also been imposed on Russians supplying aircraft parts to the Myanmar Armed Forces, after Amnesty International exposed the role of Russian arms in the country.

Ms Truss said the UK was “taking all steps we can” to hold Russia to account for sentencing two British citizens to death for fighting Russian forces in Ukraine.

Britain has sanctioned more than 1,100 people and over 120 businesses in Russia since Mr Putin ordered an invasion of Ukraine.

Dozens of other countries have levelled their own sanctions over the invasion, putting serious strain on the Russian economy.

Mr Putin recently appeared to have some cards in his hand as Moscow bargained that the west would have to lift sanctions in order for Russia to end a blockade of Ukrainian ports that has trapped desperately needed food exports.

However, Russia on Wednesday said it would allow safe passage for grain shipments from Ukraine across the Black Sea with no mention of conditions.