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A former US marine was killed while fighting alongside Ukrainian forces, his relatives told US media outlets this week.
Rebecca Cabrera told CNN that her son, 22-year-old Willy Joseph Cancel, was killed on Monday while working for a military contracting company that sent him to Ukraine.
His widow, Brittany Cancel, told ABC News that her husband “was eager to volunteer” to go to Ukraine and “went there wanting to help people".
The couple have a child who is not yet a year old.
His death comes the same week that a British military veteran, Scott Sibley, was also killed in Ukraine.
President Joe Biden's administration has repeatedly urged Americans to find alternative ways of supporting the Eastern European country without travelling there.
"We know people want to help, but we do encourage Americans to find other ways to do so rather than travelling to Ukraine to fight there," White House Press Secretary Jen Psaki told reporters on Friday.
She added: "But certainly we know a family is mourning, a wife is mourning and our hearts are with them."
The Pentagon also warned Americans against entering the war zone.
“We continue to urge Americans not to go to Ukraine … this is an active war zone, this is not the place to be travelling to,” Pentagon spokesman John Kirby told CNN.