The EU moved on Tuesday to shut down air routes taking migrants to its eastern borders after hundreds pushed to enter the bloc from Belarus.
The surge of people, mainly from Iraq and Syria, and allegedly urged on by Belarus, raised the tension in a months-long stand-off between the EU and President Alexander Lukashenko’s regime in Minsk.
Poland said the “security of the entire EU is at stake” and raised fears of an armed confrontation at the border, where migrants camped overnight amid increasing concern for their welfare.
But Mr Lukashenko said Belarus would not back down, despite fears of a confrontation that could draw in its ally Russia. “I am not a madman. I understand perfectly well where it can lead ... but we will not kneel,” he said.
EU leaders revealed they were seeking to close the migration route by pressing 13 countries to prevent their citizens flying to Belarus.
After previously leaning on Iraq, they are now urging Cameroon, Congo, Democratic Republic of Congo, Egypt, Georgia, Guinea, Jordan, Kazakhstan, Lebanon, Pakistan, Tajikistan and Turkey to consider taking action.
Belarus is accused of exploiting the migrants by luring them to the border with the false promise of a better life, to retaliate against the EU leadership, which has sanctioned Mr Lukashenko’s government.
On Tuesday, the European Council agreed to tighten sanctions on Belarusian officials, who will no longer be exempt from bureaucratic hurdles when applying for visas.
“This is part of the inhuman and really gangster-style approach of the Lukashenko regime,” said European Commission spokesman Peter Stano.
But Poland has also been criticised over its treatment of the stranded people. After Poland shut a border crossing and sent troops to shut people out, some of the migrants camped overnight in freezing temperatures, as riot police and coils of razor wire blocked their way into the EU.
“In view of the alarming situation at the border, both sides must uphold their obligations under international law,” the UN’s migration and refugee agencies said in a joint statement on Tuesday.
They urged Poland and Belarus to “prevent further loss of life” after several reported deaths and “ensure the humane treatment of migrants and refugees as the highest priority”.
Polish Prime Minister Mateusz Morawiecki travelled to the border on Tuesday morning and described the flow of people as an attack by Belarus “aimed at all of us”.
“Sealing the Polish border is our national interest. But today the stability and security of the entire EU is at stake,” he said.
“We will not be intimidated and will defend peace in Europe with our partners from Nato and EU.”
Guards used tear gas on Monday to deter the migrants, some carrying spades and wire cutters, from storming a barbed-wire fence.
Police said the situation had calmed overnight, with migrants lighting campfires and sleeping in tents near the border.
But a government spokesman, Piotr Muller, said that a further 3,000 to 4,000 migrants were massing near the border.
"We expect that there may be an escalation of this type of action on the Polish border in the near future, which will be of an armed nature,” he said.
Mr Morawiecki said he went to the frontier to show solidarity with the border guards so they would “feel that the Polish state would always be with them”.
Belarus, which denies orchestrating the migrant surge to undermine the bloc, accused Poland of deliberately escalating tension.
“We would like to warn the Polish side in advance against any provocations directed against the Republic of Belarus,” said the Foreign Ministry in Minsk.
But Poland received widespread backing from its neighbouring countries, the EU, Nato and the US, despite continuing tension between Polish and bloc leaders over the state of democracy and the rule of law in the country.
Ursula von der Leyen, President of the European Commission, said on Monday that sanctions on Belarus should be tightened. On Tuesday, a decision by the European Council put extra hurdles in the way of Belarusian officials travelling to Europe.
“Today’s decision shows once again our joint commitment to continue countering this ongoing hybrid attack,” said Ales Hojs, the Slovenian chairman of the EU's Justice and Home Affairs Council.
Minsk has been under sanction since Mr Lukashenko claimed victory in a disputed election last year and many of his opponents fled or were arrested.
Ms von der Leyen said sanctions could extend to airlines, which were shipping migrants to Belarus in what she described as human trafficking.
“Belarus must stop putting people’s lives at risk,” she said. “The Belarusian authorities must understand that pressuring the EU in this way through a cynical instrumentalisation of migrants will not help them succeed in their purposes.”
The border crisis has dragged on for months, leading to humanitarian concerns for the migrants stranded between Poland and Belarus.
Poland has declared a state of emergency in the area and fortified the border with troops and guards. It has refused help from the EU’s border agency, Frontex.
Horst Seehofer, Germany’s Interior Minister, called on democratic countries to stand by Poland as it defends the bloc’s eastern frontier.
“We want orderly migration to Europe but not politically orchestrated migration,” he said.
In Washington, State Department spokesman Ned Price said the US would stand by Poland and other countries affected by Minsk’s “unacceptable actions”.
The US “strongly condemns the Lukashenko regime’s political exploitation and coercion of vulnerable people”, he said.
“We call on the regime to immediately halt its campaign of orchestrating and coercing irregular migrant flows across its borders into Europe.”