Under Article 4, any NATO member can call for a meeting whenever, in the opinion of any of the allies, their territorial integrity, political independence or security is threatened.
"It's not enough just for us to publicly express our concern; we now need concrete steps and the commitment of the entire alliance," Prime Minister Mateusz Morawiecki said on Sunday, as quoted by Polish state news agency PAP.
He added that European Union leaders were set to discuss imposing further sanctions on Belarus, including completely closing the border.
Morawiecki also said that the 27-nation bloc should help finance efforts to build a wall on Poland's border with Belarus to prevent thousands of migrants from illegally crossing into the EU, the PAP news agency reported.
Polish Prime Minister Mateusz Morawiecki. Photo: PAP/Łukasz Gągulski
'Further provocations'
The Polish defence ministry on Monday reported "further provocations" by Belarusians and said that more groups of migrants were being brought to the Poland-Belarus border crossing at Kuźnica "by the Belarusian services."
"The sounds of shots, probably from blank ammunition, are a daily reality faced by our soldiers and officers," the Polish defence ministry said in a tweet.
In another post, it said that "the migrant march" to the border crossing "took place under the control of the Belarusian services."
New attempts to storm border 'highly likely'
Stanisław Żaryn, a spokesman for Poland's security services, warned in a Twitter message that it was "highly likely" that new groups of migrants "transported by the Belarusian services to the Belarus-Poland border crossing in Kuźnica" would attempt to "storm the border."
"The Polish border guards, police officers and soldiers are standing ready," Żaryn tweeted.
EU, NATO, US, UN nations condemn Belarus
US State Secretary Antony Blinken at the weekend reaffirmed America's support for Poland amid the migrant crisis on the EU member's border with Belarus.
Last week, the United States and European members of the UN Security Council condemned Belarus for the “orchestrated instrumentalization" of migrants as tensions rose along the Polish-Belarusian border.
The United States voiced concern over "disturbing images and reports" from the Polish-Belarusian border, and condemned Belarus for "orchestrating" migrants flows to Europe.
NATO condemned the use of migrants by Belarus "as a hybrid tactic," with its Secretary-General Jens Stoltenberg voicing solidarity with Poland amid the border standoff.
Meanwhile, European Commission head Ursula von der Leyen called for EU member states to approve new sanctions against Belarus, which she said was responsible for a "hybrid attack" on the Polish border using migrants.
The European Union has accused Belarus of encouraging thousands of migrants from the Middle East and Africa to cross into EU countries via Belarus, as a form of hybrid warfare in revenge for Western sanctions on Minsk over human rights abuses, the Reuters news agency reported.
Poland and the Baltic states have accused Belarus's strongman leader Alexander Lukashenko of organising a wave of illegal migrants seeking to enter the bloc as part of what officials have called a "hybrid war."
In late September, Polish lawmakers voted overwhelmingly to extend a state of emergency in parts of two regions along the country's eastern border with Belarus by two months amid a growing migrant surge.
The state of emergency gives authorities broader powers to monitor and control the movement of people on the Polish-Belarusian border, which is also the eastern border of the European Union.