(CNN) Russia is using rape and sexual violence as part of its "military strategy" in Ukraine, a UN envoy said this week.
The claim follows data released by a panel of UN experts recently that verified "more than a hundred cases" of rape or sexual assault incidents reported in Ukraine since February.
"When you hear women testify about Russian soldiers equipped with Viagra, it's clearly a military strategy," Pramila Patten, UN Special Representative on Sexual Violence in Conflict, said in an interview with AFP on Thursday.
She added that many cases involved children and also said that the true number of victims was likely to be far higher than official figures suggested because sexual crimes are often "under reported."
"There are many cases of sexual violence against children who are raped, tortured and sequestered," Patten said.
"I have not stopped since February to emphasize the importance of having credible investigations into these cases of violence."
Since the Russian invasion began, Ukrainian officials have repeatedly accused Moscow's forces of sexually abusing women and children, claiming they are using rape and other sexual acts as weapons of war.
Ukraine's Deputy Minister of Internal Affairs Kateryna Pavlichenko in June said that police received around 50 complaints of sexual crimes committed by Russian soldiers.
Prosecutors are also investigating rape allegations in the Kharkiv region after Ukrainian forces recently recaptured territory there.
CNN has spoken with Ukrainian women, one of them a pregnant 16-year-old, who shared harrowing accounts detailing sexual assault.
CNN could not independently verify the latest claims by the UN.
Russian authorities have denied allegations of war crimes in Ukraine.