Thousands of people are stranded at the EU's eastern border in freezing weather, with Warsaw accusing Russia and Belarus of using the migrants to threaten European security.
Polish Defense Minister Mariusz Blaszczak told public broadcaster PR1 that Tuesday night had seen "many attempts to breach the border." However, he added, all those who crossed into Poland were stopped.
What did Germany's foreign minister say?
Maas said in a statement that Belarusian President Alexander Lukashenko is "unscrupulously exploiting" the migrants and sending them to the border region.
"We will sanction all those who participate in the targeted smuggling of migrants," the German foreign minister asserted, while adding that the EU will push to "extend and tighten ... sanctions against Lukashenko's regime."
Any fresh sanctions could target not only countries involved in smuggling the migrants but also airlines that faciliate their travel to Europe.
Maas said the images of the thousands of migrants at the Polish-Belarusian border are "appalling."
Maas' remarks come after German Interior Minister Horst Seehofer told the Tuesday edition of Germany's Bild tabloid that the EU needs to do more to help Poland secure its border. Poland has refused to let the migrants in.
Mafred Weber, chair of the center-right EPP bloc in the European Parliament, told DW that the EU had to target Lukashenko's "oligarchic system."
"It's not a normal migration situation like we had in 2015, when people were fleeing from war in Syria," the German EU lawmaker said. "We are now experiencing a hybrid war and Europe has to be united."
How has the EU responded so far?
European Commission President Ursula von der Leyen called for "approval of extended sanctions" against Belarus on Monday.
The bloc has previously approved four rounds of sanctions targeting 166 people and 15 entities linked to Lukashenko's regime.
Tensions have been fraught between the EU and Belarus since the state-ordered hijacking of a Ryanair flight over Belarusian territory in May.
The EU has also condemned last year's presidential election in Belarus as neither free nor fair, with Lukashenko having declared a landslide victory against opposition candidate Sviatlana Tsikhanouskaya.
Why is there a crisis at the Poland-Belarus border?
EU officials accuse Belarus of "weaponizing" the migrants against the 27-member bloc in retaliation for previous sanctions against Minsk. They say Belarus is flying migrants to the capital from abroad on special visas and taking them to the EU's doorstep.
Lukashenko has denied that his government is orchestrating the crisis.
Since July, large numbers of migrants from Iraq, Syria, Yemen and other troubled regions have been attempting to illegally enter the EU via Poland, Latvia and Lithuania.
At the same time, Poland has been facing accusations of pushing migrants back into Belarus instead of giving them a chance to ask for asylum.
wd/nm (AFP, dpa)