Russian President Vladimir Putin on Friday backed plans to allow volunteers, including from abroad, to fight in Ukraine, where he has sent thousands of Russian troops in what he calls a "special military operation."

"If you see that there are people who want on a voluntary basis (to help east Ukraine's separatists), then you need to meet them halfway and help them move to combat zones," Putin told Defense Minister Sergei Shoigu during a televised security council meeting.

According to Shoigu, more than 16,000 volunteers – mostly from the Middle East – have appealed to join the military action.

"As for the supply of arms, especially Western-made, which ended up in the hands of the Russian army, of course I support the possibility of transferring them to the military units of DNR and LNR," Putin said referring to the breakaway Donetsk and Luhansk regions in Ukraine's east.

Putin also ordered that Shoigu prepare a separate report on strengthening Russia's western borders "in connection to the actions that NATO countries are taking in this direction."