A 79-year-old Ukrainian woman is among those training to defend her country, as Russian troops hover just over the border.
Valentyna Konstantynovska lives in Mariupol and attended military training on Sunday so she could learn how to defend herself.
The training was run by members of Ukraine's Special Forces and included how to assemble and dissemble a gun, how to load ammunition, and how to aim at a target.
Ms Konstantynovska said: "I'm ready to shoot.
"If something happens, I will defend my home, my city, my children.
"I will do this because I think I'm ready for it.
"I don't want to lose my country, my city."
Russia has denied any plans to invade but it has more than 100,000 soldiers near the Ukrainian border, and has sent more to exercises in neighbouring Belarus.
The US has said that the extent of the build-up has given Russia the ability to invade Ukraine within days, a warning which sparked many countries to tell their citizens and diplomats to leave.
One of the Special Forces unit members Kyrylo Berkal said telling diplomats to leave Ukraine was the correct decision because the situation could be "dangerous for them".
But he added that people in Ukraine should not panic, because allies would still help them.
"My message is that we must make more actions to stop Russian invasion together," he added.