UK war crime experts are to help Ukraine investigate atrocities committed by Russian troops, amid allegations that rape is being used as a weapon of war by the invaders.
Foreign Secretary Liz Truss, on a visit to the the International Criminal Court in the Netherlands said the experts will arrive next month, to help collect a "wide range of evidence" to ensure justice is done for the people of Ukraine.
"We've seen appalling war crimes committed, the use of rape and sexual violence... we've been talking today about the urgency of making sure that justice is done and that also we call out rape as a use of weapon in war," she said.
The UK is also using British intelligence, to "help show the links between what is happening on the front line and the Russian authorities, because it's important that everybody in the chain of command is held to account," she added.
What will UK war crimes experts do in Ukraine? Liz Truss explains:
It comes after the death of a British military veteran in Ukraine and as the Foreign Office urgently seeks more information following reports of two British humanitarian workers being detained by Russian forces in the country.
The Foreign Office said the team of experts, due to arrive in neighbouring Poland in early May, will support the Ukrainian government in gathering evidence and prosecuting war crimes and will include experts in conflict-related sexual violence.
Ms Truss said: "This is about collecting a wide range of evidence - witness statements, forensic evidence, video evidence," she told broadcasters.
"We will also use British intelligence to help show the link between what is happening on the front line and the Russian authorities, because it is important that everybody in the chain of command is held to account.
"The priority now is collecting the evidence as soon as possible and making that happen and also bringing perpetrators to justice because bringing perpetrators to justice is also about preventing further atrocities taking place in Ukraine, demonstrating to people that if they do commit war crimes, if they do use rape as a weapon of war, they will be held to account.
"We are looking at all possible ways, including how the crime of aggression can be prosecuted."
Ms Truss is on Friday meeting in The Hague with the president of the International Criminal Court (ICC), which has opened a probe into alleged war crimes in Ukraine.
Moscow does not recognise the authority of the ICC, presenting obvious difficulties.
Meanwhile, the Ministry of Defence said Russia is paying a high price for limited gains of land in Ukraine’s east.
“The Battle of Donbas remains Russia’s main strategic focus, in order to achieve its stated aim of securing control over the Donetsk and Luhansk oblasts,” the department said in its latest intelligence update.
“Due to strong Ukrainian resistance, Russian territorial gains have been limited and achieved at significant cost to Russian forces.”
The two British civilians held in Ukraine were working as humanitarian aid volunteers when they were captured by the Russian military on Monday at a checkpoint south of the city of Zaporizhzhia in the south-east of the country, according to the UK non-profit organisation Presidium Network.
International Trade Secretary Anne-Marie Trevelyan told Sky News: “The Foreign Office is doing all it can to support and identify these two people.”
Tributes were paid to British military veteran Scott Sibley, reportedly fighting in support of Ukrainian forces, after the Foreign Office confirmed a British national has died in Ukraine and another is missing without identifying the pair.
The families of both are being supported, a spokesman said, declining to give names or further details.
Fundraisers have received donations of more than £10,000 for the veteran’s family, with Craig Grant writing on one Gofundme page: “To me he was a friend like no other and the bravest person I’ve had the pleasure to have known, he was as good as a brother to me.”
Tributes were also left on the Logistic Support Squadron Facebook page, where a picture was posted alongside the comment: “This week the Sqn has lost a former serving soldier. A man that showed Commando spirit until the end. RIP. Scott Sibley.”
A small number of serving British personnel are believed to have gone absent without leave to join the resistance against the Russian invasion, while veterans and Britons without combat experience are thought to have also travelled to Ukraine.
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There was initially confusion on the government’s position after Ms Truss, in comments during an interview to the BBC on February 26, said she would “absolutely” support UK nationals who chose to fight for Ukraine.
However, she later rowed back on those comments, insisting she had been “expressing support for the Ukrainian cause” in her remarks and that there are “better ways” to contribute to the country’s defence.
Meanwhile, around 8,000 British Army troops are to take part in exercises across eastern Europe to combat Russian aggression in one of the largest deployments since the Cold War.
Dozens of tanks will be deployed to countries ranging from Finland to North Macedonia this summer under plans that have been enhanced since the invasion of Ukraine.
Defence Secretary Ben Wallace said the “show of solidarity and strength” will see UK service personnel joining with Nato allies and those from the Joint Expeditionary Force alliance, which includes Finland and Sweden, for the exercises.