EU Council chief Donald Tusk rebuked fellow European leaders on Thursday by calling arguments over how to accommodate refugees "naive" as long as Europe fails to stop them surging over its borders.
German Chancellor Angela Merkel was at a gathering in Madrid where Tusk, a former Polish prime minister, criticised fellow conservatives over the handling of the migration crisis. Others present included Hungarian Prime Minister Viktor Orban and European Commission President Jean-Claude Juncker.
Tusk, who chairs summits of EU national leaders, named no names but his blunt language offered a glimpse of what diplomats say is an increasingly testy debate behind the scenes between those like Tusk who stress the urgency of tightening Europe's borders and others including Merkel pushing for states to show "solidarity" and share responsibilities for refugees among them.
"We can no longer allow solidarity to be equivalent to naivety, openness to be equivalent to helplessness, freedom to be equivalent to chaos. And by that, I am of course referring to the situation on our borders," Tusk said in a 5-minute speech.
As migrants and bad weather make for chaos in the Balkans, Merkel's push for a crisis meeting with regional leaders that Juncker will host on Sunday has raised concerns of a rift between those emphasising humanitarian issues and those stressing security, even if all agree both are important.
Addressing the European People's Party, an alliance of centre-right movements, Tusk said the leaders present must not "abdicate" their "primary duty" to protect their territory. "If you want to help others, you need to first be able to take care of yourself and your loved ones," he said, praising host Prime Minister Mariano Rajoy for curbing illegal migration to Spain.
Merkel, as she repeated when she spoke later, supports the range of measures the European Council has agreed this year, including frontier controls but also pilot schemes to relocate Syrian refugees and other asylum-seekers around the bloc.
Under pressure at home, however, as Germany prepares to take in most of a million or so migrants this year, her push for a permanent relocation mechanism setting binding national quotas has met fierce resistance, notably from easterners like Orban.
Critics say Merkel, Europe's most influential leader, risks distracting the EU from efforts to stem the inflow and may even encourage more immigrants by emphasising a need to welcome them. Her allies are sceptical that people can be kept out and want Europe to be organised to cope with new arrivals next spring.
Tusk, whose role is to build consensus among EU leaders but who often makes little secret of his personal views, called for an end to "this completely unnecessary argument between the proponents of protecting external borders and the advocates of solidarity and openness", and for a "rational hybrid" of both.
Noting both camps were in the audience, he balanced his call for more border security by calling arguments against relocation "shameful" and warning against "populism and xenophobia". Those are charges commonly levelled at Orban, who has fenced Hungary's borders and speaks of a Muslim threat to European culture.
Tusk said: "Our political aim should be to strengthen Europe against right-wing extremists, and not to become like them."