The mother of a Minnesota man taken prisoner by Russian troops in Ukraine is distraught over the fate of her "amazing son," an English teacher who was taken off a bus as he tried to escape the war-torn nation.

"We don't know exactly where he is at. We don't know if he's got food or shelter," said Tina Hauser of Winona. "I don't know if he's alive."

Her son, 28-year-old Tyler Jacob, went to Ukraine in November, taking a job teaching English so he could be with his longtime girlfriend, a Ukrainian. The couple married in January and lived in Kherson, a southern port on the Black Sea.

Jacob, a graduate of Winona High School, stayed in the country even after Russia invaded last month, but he finally decided he should try to get out. Along with some friends from Turkey, he got on a bus headed for the Turkish border but was detained Sunday at a checkpoint in Armiansk, a city in the Ukrainian region of Crimea that has been under Russian control since an invasion in 2014.

Jacob had resisted pleas to leave earlier, his mother said.

"He just is so in love with everything there that he didn't want to leave," she said. "He's like, 'Mom, I've got a job, I need to take care of my life over here.' "

Hauser said she got a call Wednesday morning from the U.S. Embassy in Moscow, "and the news they gave me was not the best."

Jacob is the second U.S. citizen detained by Russia, she was told, and she should expect "a long, slow process" to determine his fate.

Hauser said she has spoken with officials working for U.S. Sen. Amy Klobuchar and that U.S. Sen. Tina Smith's office has also been alerted.

Jacob grew up in Winona as an avid hunter, fisherman and swimmer. He loves riding motorcycles and tinkering with small engines. Until he took the teaching job, he was working in the parts department of a truck dealership, his mother said.

He wrote a book about his romance, she said. "Love's Cocktail: The Story of an American Immigrant Who Finds Love in Ukraine" is a lightly fictionalized account based on his own experience.

His wife is "beautiful — she's just amazing," Hauser said. The wife's name is not being released, to protect her safety.

Hauser said she and Jacob's father, who are divorced, are joining forces to spread the word of his detention and build support.

"We're working together as a really good team this way," she said.

Since the war started more than three weeks ago, Hauser said, she's only been getting two or three hours of sleep a night.

"I force myself to eat," she said. "I am holding it together right now, but I just had a crying fit.

"It's been a real roller coaster."