Ukraine is calling on its citizens to join the fight against Russia, and its military says all they need is ID

• Ukraine has urged regular citizens to take up arms, making the enlistment process simple. 
• People can join the fight and will be given weapons as long as they have an ID, Ukraine's Armed Forces tweeted.
• Many civilians have been training for this moment, undeterred by Russia's military might. 

As Russia's military invades Ukraine and attacks its cities, Ukraine's president has called on citizens to take up arms and join the fight. They can join and will be given weapons as long as they have ID, according to Ukraine's Armed Forces.

"All those who are ready to take up arms, join the ranks of the area defense forces of the Armed Forces of Ukraine. We simplified procedures. Only your ID is needed. We give weapons to all patriots!" Ukraine's Armed Forces said in a tweet.

—ЗС УКРАЇНИ (@ArmedForcesUkr) February 24, 2022

The tweet linked out to a Ukrainian government Facebook page that attributed the call to arms to the Ukrainian defense minister.

Russian President Vladimir Putin has launched a major military operation against Ukraine, and it may be just the beginning. A senior US defense official told reporters Thursday the US military would describe recent developments in Ukraine "as an initial phase" of a "large-scale" Russian invasion.

While Ukraine benefits to a certain extent from fighting to defend its own territory, Russia's military outmatches Ukraine's on every level, meaning that the Ukrainian military may not be able to hold up against a full-scale invasion.

If that is the case, regular citizens may need to take up arms to bolster the country's military capabilities. Ukraine's president, Volodymyr Zelensky, suggested as much in a tweet Thursday.

—Володимир Зеленський (@ZelenskyyUa) February 24, 2022

Many regular Ukrainian citizens  – from dentists to architects to bakers – have been training for this moment, gathering on the outskirts of Kyiv and other cities to practice combat, undeterred by Russia's military might. They received training from former and current military members.

"We will never surrender," Ukrainian architect Denys Semyroh-Orlyk told The Wall Street Journal earlier this month, adding, "We are using every opportunity to train. So I think Putin should be afraid of us."