"I don't plan to stay here forever," Martin tells Reuters. "I plan to repel [a Russian attack] and come back home so that my daughter will later say, 'Wow, father, you managed to stop a superpower with your own hands.'"
U.S. officials have warned Russia might launch a new attack against Ukraine as early as the second half of January when the ground will be harder, making it easier for tanks and other armor to move swiftly.
Russia has demanded security guarantees from the West in order to defuse the current crisis.
Moscow denies it is planning a new military offensive and accuses Kyiv of building up its own forces in the east of the country.
