in an email to Reuters, said U.S. citizens are urged not to travel to Ukraine.
Not all volunteers want to fight.
In Quebec, 35-year-old physician Julien Auger was preparing to leave his young family to become a medic with Ukraine's health ministry and provide "neutral" humanitarian aid.
"Global opinion and support is the key right now to solving the conflict," said Auger, a father of two who provides palliative care at a hospital in Saint-Jérôme.
In online groups, military veterans warned volunteers who lacked combat training they were heading into a conflict where inexperience could be a liability for themselves and others.
That did not stop those like Tai B., 23, who studied journalism in New York.
"I'm not looking to be a hero, or a martyr, I just want to finally do something right," said Tai, who can cook, do basic mechanics and knows how to handle a firearm. He said he has contacted Ukraine's U.S. Embassy staff about enlisting in Zelenskiy's "international legion."
Hyde, a 28-year-old from the U.S. Midwest, said he was already in Kyiv and expected to start military training on Tuesday.
"I cannot bear the thought of Europe once again being plunged into warfare," said Hyde, who described himself as a gun enthusiast and avid survivalist with no combat experience. He expects to be given a helmet, body armor, knee pads and eventually a rifle.
In Austin, Texas, a software developer said he would draw on his experience as a U.S. Army cadet to fight for Ukraine.
"If they're willing to defend democracy then I think those that benefit from a democratic society are duty-bound to support them," said the 25-year-old, who asked that his name not be used. "I'm not telling my parents until I head to the airport."
(Reporting by Andrew Hay in New Mexico and Rod Nickel in Winnipeg; Additional reporting by Barbara Goldberg in New York; Editing by Sandra Maler and Stephen Coates)