The fence was built in just over five months and is designed to stem illegal migration from Belarus.
Speaking in the border town of Kuznica on Thursday, Morawiecki said that the fence was "necessary to safely protect the Polish border and focus on stretches where the fight for the future of Europe and Poland is taking place."
The prime minister was referring to an attempt by the Belarusian regime to destabilise Europe by bringing in thousands of migrants from the Middle East and Africa and encouraging them to cross into Poland and Lithuania, a move that was made in retaliation for sanctions the EU had imposed on Minsk for its brutal crackdown on democratic opposition.
"Internal and external security is our top priority, our raison d'etre and we'll pursue it against all odds," Morawiecki said and added that, "This fence is an expression of our effectiveness, responsibility, foresight and predictability."
Mariusz Kaminski, the interior minister, said that the migration crisis stoked by Belarusian strongman Alexander Lukashenko in the second half of 2021, "was preparation for (Russia's - PAP) war against Ukraine."
"It was a Russian scenario, we had no doubt about it," he added.
Maciej Wasik, Kaminski's deputy, said the electronic component of the new fence, including cameras, night vision and motion detection equipment, was to be operational by September. (PAP)