In a sign of European urgency to resolve what it calls an artificial border crisis created by Minsk, Germany's Chancellor Angela Merkel spoke by phone on Wednesday for the second time in three days to Belarus's President Alexander Lukashenko.
A day after Polish border guards used water cannon against migrants hurling stones, the situation at the frontier appeared to have grown calmer. Polish and Belarusian border guards both said some 2,000 migrants were right at the border fence.
The head of the EU executive, Ursula von der Leyen, announced the aid, while saying it was up to Lukashenko to halt a crisis that Europe believes he created deliberately.
"We are ready to do more. But the Belarusian regime must stop luring people and putting their lives at risk," she said.
The EU says Minsk has flown in thousands of migrants from the Middle East to push them to cross illegally into the bloc, in order to put pressure on Europe in retaliation for sanctions imposed against Belarus over human rights abuses.
Belarus denies fomenting the crisis but says it cannot help end it unless Europe lifts sanctions it imposed since Lukashenko cracked down on opponents after a disputed election last year.
Poland's Defence Minister Mariusz Blaszczak told Polish public radio on Wednesday the crisis at the border was likely to last months: "We have to be prepared that this situation on the Belarusian border won't settle swiftly," he said.
Several thousand people have been camped out in the woods as winter approaches, suffering from frost and exhaustion, and barred either from entering Poland or returning into Belarus.
At least eight have died at the Polish border since the crisis started this summer. Neighbouring Lithuania and Latvia have also experienced a sharp spike in attempted irregular crossings from Belarus.
The EU has called on Russia to make Lukashenko end the crisis. Moscow denies any direct role but has offered to mediate, while also demonstrating support for Lukashenko by staging military exercises jointly with Belarus near the border.
Merkel's phone calls with Lukashenko are an unusual sign of direct outreach to a leader Europe has shunned as illegitimate since last year's election. In statements following the calls, Merkel's spokesperson Steffen Seibert referred to him as Mr Lukashenko, without referrence to his title as president.
Merkel "stressed the need, with the support of the United Nations High Commissioner for Refugees, the International Organisation for Migration and the cooperation of the European Commission, to provide humanitarian aid and repatriation facilities to the affected people," Siebert said of Wednesday's call.
The EU has blacklisted Lukashenko and dozens of Belarusian state officials and introduced economic sanctions on trade since the crackdown that followed last year's election. It is now expanding sanctions on travel agents and airlines involved in what it calls "human trafficking" behind the border crisis.
The European Bank for Reconstruction and Development (EBRD) might also halt investments in Belarus, a source told Reuters. The bank currently has 914 million euros ($1.03 billion) in projects there.
The bloc has so far largely supported Poland's nationalist government in taking a hard line at the border, fearing that allowing migrants to cross would encourage more to try.
Police in Germany - a top destination for immigrants once they reach the EU - say they have registered 9,549 illegal entries from Belarus via Poland this year. In figures that show how suddenly the issue emerged, they reported only 26 such cases between January and July, rising to 474 arrivals in August and 5,285 in October.
Preventing uncontrolled immigration has been a central political issue for the bloc since 2015, when more than a million people arrived from the Middle East and Africa, triggering feuds between member countries over how to share responsibility for caring for them.
The EU was caught off guard, its welfare and security systems were strained and the ensuing chaos triggered a surge in nationalist movements, also contributing to support for Britain's exit from the bloc.
The EU has since tightened external borders and paid to host migrants in countries such as Turkey, and stop them along migration routes in Libya and elsewhere, often in dire conditions. Rights groups decry the EU's restrictive tactics as aggravating human suffering.
"The European Union doesn't have a good common migration policy, despite obvious need for one after the previous migration crises," said Linas Kojala, director at the Eastern European Studies Centre think-tank in Vilnius.
"Each time it needs to look for ways to extinguish fires. And it lacks tools to use against regimes hostile towards it, including Belarus and Russia."