Ukrainian President Volodymyr Zelensky and Polish President Andrzej Duda discussed on the phone Wednesday, a hybrid attack on their countries, according to the Ukrainian presidency.

Zelensky and Duda underlined that "there is a hybrid attack, the proper response to which requires joint efforts and cooperation."

They addressed the migrant crisis at the Belarus-Poland border and the security situation in eastern Ukraine as well as the Nord Stream-2 pipeline project.

NATO and the EU consider Belarus’ approach toward migrants a hybrid attack meant to destabilize and undermine security in European countries through non-military means.

Since August, the European Union countries bordering Belarus -- Lithuania, Latvia and Poland -- have reported a dramatically growing number of irregular crossings.

More than 8,000 people have tried to enter the bloc via the Belarus-EU border in 2021, up sharply from just 150 last year.

According to the EU, Belarus reaches out to potential travelers through seemingly official channels, including diplomatic missions and travel agencies, and invites them to Belarus by offering them visas. They are then allegedly guided to the EU border.

In the last week, at least 2,000 people, including women and children, have been stuck at the Belarusian-Polish border area in dire conditions.