EU foreign policy chief Catherine Ashton has announced that all EU members will recall their ambassadors to Minsk.
This move comes after Belarus asked the Polish and European Union ambassadors to leave the country and recalled its own envoys from Poland and the EU "for consultations" in a tit-for-tat response to an expansion of sanctions against it by Brussels.
Belarusian Foreign Ministry spokesman Andrey Savinykh accused the EU of "continuing with its policy of unabashed pressure," and said, "In response, Belarus will forbid entry to Belarus to those individuals who helped introduce those restricting measures."
"The head of the EU delegation to Belarus and the ambassador of Poland to Belarus have also been asked to return to their capitals to bring the message to their leadership about the strong view in Belarus that any pressure or sanctions are unacceptable," Savinykh said. "If the pressure on the Republic of Belarus is to continue, other measures to defend our interests will also be taken."
Within hours, the EU responded through Ashton's spokeswoman, Maja Kocijancic, who said: "In expression of solidarity and unity, it was agreed that the ambassadors of the EU member states in Minsk will all be withdrawn for consultations to their capitals.All EU member states will also summon Belarusian ambassadors to their foreign ministries."
Subsequently, European Parliament President Martin Schulz said that "instead of choosing increasing self-isolation, Minsk should make the right choice for its people and open itself towards democracy."
Schulz said that as a first step, Belarus should "release unconditionally and rehabilitate all political prisoners."
State Department spokesman Mark Toner said that the United States joins its European partners "in calling on Belarus to end its repression of civil society and the democratic opposition."
Belarus expelled the U.S. ambassador to Minsk in 2008.
The unfolding diplomatic row came with a fresh reminder of the perceived abuses that the West has repeatedly condemned in Belarus, as the wife of a hunger-striking activist sentenced last week to two more years in prison told RFE/RL's Belarus Service that she'd been allowed to see her husband
and he looked "half-alive."
Poland is one of Europe's biggest critics of the government of President Alyaksandr Lukashenka, who has ruled Belarus since 1994 with Soviet-style authoritarianism.
Warsaw issued a statement saying it regards Minsk's move as "an unfriendly step taken by Belarus towards the whole European Union."
On February 28, the European Council increased by 21 the number of sanctioned individuals connected with Lukashenka's regime who were targeted because of the ongoing repression of political opposition. More than 200 people were already on the bloc's blacklist.
The EU sanctions target actions Minsk has taken since the December 2010 presidential election, which Lukashenka won amid allegations of vote fraud. More than 700 people, including seven opposition political candidates, were arrested during and after the ensuing mass protests.
At a news conference in Brussels, EU enlargement commissioner Stefan Fuele said Minsk's reaction threatened to overshadow the bloc's goals on Belarus.
"Whatever is taking us away from the most important tasks -- and as I see them, the task No. 1 is to release all political prisoners and to rehabilitate them and second, to reengage with Belarus to the benefit of the citizens of Belarus -- is unhelpful and counterproductive."
Swedish Foreign Minister Carl Bildt called Lukashenka's move a sign of "weakness and desperation" as the country's economy -- starved of investment, trade, and international funds -- teeters on the brink of collapse.
"[Lukashenka] has tried to manipulate us in different ways and to influence and threaten us in different ways," Bildt said. "Now he tries to do something that he thinks will put pressure on us. We interpret this as weakness and desperation. He is in a very tough situation. He is now burning bridges and this will have negative consequences in the future."
German Foreign Minister Guido Westerwelle said Germany would recall its ambassador to Belarus and suggested other EU member states follow suit.
"This is the last dictatorship, this is the last dictator in Europe, and we will not let ourselves be intimidated by such actions against one European institution or against one member state," Westerwelle said.
Written by Heather Maher in Washington with reporting from Brussels by Rikard Jozwiak, from RFE/RL's Belarus Service, and additional Reuters reporting