Russian officials have described one of their top priorities at tomorrow's summit between President Trump and Vladimir Putin to be normalizing relations with the U.S. on topics beyond Ukraine.

And that concerns European officials who consider Russia a long-term threat and believe Moscow is producing enough weapons to one-day attack members of NATO, too.

Nick Schifrin recently sat down with Estonia's defense minister

about the Baltic nation's increasingly fortified border with Russia,

a story documented with the help of journalists

from the University of British Columbia's Global Reporting Program.

For 16 hours a day, this Lithuanian factory is buzzing.

Massive machines.

Alongside workers build barriers by the hundreds.

They're called dragons teeth, concrete pyramids, each one hundreds of pounds.

And more than foot-thick metal rod roadblocks, they're called hedgehogs, a storybook name

for a serious purpose.

Protection against a Russian invasion, like in Ukraine.

It's about the defense of our country and the security of our people.

Donadas Yankauskas is the CEO of Jalmesta.

Its barriers might be low-tech.

But they're highly efficient.

The size, weight, and angle of the dragon's teeth stop enemy tanks in their tracks.

And in northeast Lithuania, American and Lithuanian troops train fewer than 10 miles from the Belarusian border.

Assault one!

Where hundreds of dragon's teeth are already glaring at the ready to stop Russian tanks.

Lithuania is not alone fearing an attack from neighboring Russia, up the road in eastern

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