A sign outside a temporary refugee center in Neu-Isenburg near Frankfurt | EPA Berlin threatens neighbors over migration Central Europe could lose cash and open borders over German irritation on lackluster refugee effort.

BERLIN — Germany warned Eastern European countries of serious consequences if they don’t drop their resistance to accepting more refugees, reflecting Berlin's growing frustration at the unwillingness of its neighbors to help alleviate the crisis.

Speaking at a joint press conference Monday after agreeing to earmark an additional €6 billion to deal with the influx of asylum seekers, German Chancellor Angela Merkel and Vice Chancellor Sigmar Gabriel stressed that the rest of Europe, particularly countries in the east, needed to do more to stem the crisis instead of relying on countries like Germany, Austria and Sweden shoulder the burden.

“Eastern Europe enjoys the greatest economic advantage from open borders,” Gabriel said. “It is in Germany’s interest to maintain these open borders but everyone should be aware that if (the refugee burden) is concentrated on these three countries the debate will take another direction.”

Gabriel hinted that EU funding for countries could also be at risk if a solution to the refugee crisis wasn’t found soon. Merkel echoed his comments, adding: “What isn’t acceptable is that some maintain this situation has nothing to do with them.”

Berlin’s not-so-subtle threats of retribution suggest Germany is quickly losing patience with its European partners over their reluctance to play a bigger role in managing the crisis. While Germany estimates it will take in as many as 800,000 refugees this year, some countries in Eastern Europe have taken almost none and have rejected calls to do more.

Merkel said she hoped proposals for a more even allocation of the refugees, due to be presented by European Commission President Jean-Claude Juncker in his state of the union address on Wednesday, would be accepted by other capitals.

Critics, including Hungarian Prime Minister Viktor Orbán, say Germany has only itself to blame for the crisis.

By agreeing to waive normal procedures and accept thousands of asylum seekers stranded in Hungary in recent days, Germany has encouraged more refugees to come, those critics say. Though that is undoubtedly true, Berlin, under pressure from ordinary Germans, doesn’t see any other option in the face of the dramatic events in Hungary in recent days.

Though Germans have shown a surprising openness to take in the newcomers, it’s unclear if that enthusiasm will last amid rising costs and myriad logistical challenges.

The harsh tones from Merkel and Gabriel on Monday suggest they may also be worried about a backlash.

They said estimates of the total cost of the refugees this year to federal and local governments of about €10 billion were roughly accurate. Though Germany is well positioned to deal with the financial costs of the crisis due to its robust economy and solid finances, it can't manage alone for the long haul, they warned.

“We need a show of strength from the European Union,” Merkel said.

Gabriel, calling the crisis the greatest challenge facing Germany since reunification, urged his countrymen to confront it with a mix of “confidence and realism.”

Central Europeans are adamant in rejecting any bid to impose refugee numbers by quota, insisting that each country should decide on its own how many newcomers to accept.