Merkel, in an address to Germany's Bundestag on the eve of a two-day Brussels summit, said Europe should work to improve the lives of refugees in Turkey, Lebanon and Jordan as the way to meet "our goal" of reducing migrant flows into Europe.

She described as "intolerable" the situation for besieged civilians in and around northern Syria's war-torn hub of Aleppo, saying "nothing should be left undone" in trying to establish a no-fly zone to save "many human lives."

Washington has long rejected the idea, fearing it could draw US forces into Syria's civil war. Moscow on Tuesday warned that obtaining consent from Damascus and UN Security Council approval could end up being lengthy.

Merkel reiterated in her government statement to parliament on Wednesday her view that Europe must concentrate on ameliorating the causes of refugee flight from Syria, saying it was worthwhile to "continue going down this path."

Germany would make a "significant contribution" as part of the 11 million euros ($12.2 million) in humanitarian aid pledges given at a recent donors' conference in London, she said.

The UN's World Food Program must not again be forced to reduce its handouts to refugees, which last year had been one of the reasons that refugees headed to Europe, she said.

Fence will bring consequences

She warned Visegrad nations wanting completion of a fence along the Macedonian-Greek border that their move amounted to isolationism and would have wide-ranging consequences for a Europe based on free movement, including trade in goods and services.

Refugee arrivals amounted to a "rendezvous with globalization," Merkel said, saying the EU "must learn to protect its maritime [external] border."

That included 900 kilometers (560 miles) of maritime frontier between Greece and Turkey, she said, as well as Italy's Mediterranean border crossed by migrants arriving from Libya.

Macedonian soldiers erect the border fence

European 'shambles,' says Left

Opposition Left party parliamentary leader Sahra Wagenknecht accused Merkel of contributing to a "European shambles" over asylum policy.

"Whoever seriously thought that Europe could be governed from Berlin should not be surprised when the wind now blows in his face," Wagenknecht said.

Praise for diplomats

Chancellor Merkel praised diplomats, including German Foreign Minister Frank-Walter Steinmeier, for their efforts to establish a ceasefire in Syria coupled with humanitarian deliveries.

Durable diplomacy was needed despite setbacks, she said.

"Despite all the critical findings in surveys, more than 90 percent [of German voters] say as they did before, that whoever has to flee terror, war or persecution, should have the possiblity to be admitted into Germany and to find shelter. I think that's wonderful," she said.

Reacting to lingering criticism of the German government's decision last September to keep its border open to refugees, European Commission President Jean-Claude Juncker firmly backed Merkel in an interview with mass circulation newspaper "Bild" on Wednesday.

Merkel would "outlast all her critics in office," Juncker said. "It is political leadership to say 'we can do it.' Anything else is capitulation to the populists."

Backing also came from Germany's Catholic bishops.

Their chairman, Cardinal Reinhard Marx, said the federal government was doing much to ensure that refugees were given shelter and this political stance should not be called into question, Marx said.

"And, the states in all of Europe are being called upon to make their justified contribution in the fields of refugee protection and asylum," he said.

Remain 'active' member

Merkel prefaced her pre-summit remarks at Wednesday's Bundestag session by urging Britain to remain an "active member" of the 28-nation European Union.

She described elements of EU reforms to be submitted to the Brussels summit by British Prime Minister David Cameron as "justified."

The EU, however, must not sacrifice its fundamental principles of free movement and non-discrimination, Merkel said.

"These principles are not up for disposal," Merkel said, adding any change to EU treaties would not be immediate.

ipj/kms (AP, AFP, Phoenix)