By Michelle Martin
BERLIN (Reuters) - German Chancellor Angela Merkel said Europe needed to protect its external frontiers as it faces the greatest influx of refugees since World War Two - a crisis that she said was "testing Europe's mettle".
Hundreds of thousands of refugees and migrants have arrived in Europe this year from the Middle East, Africa and Asia, many fleeing war or poverty.
Speaking in a weekly video podcast released on Saturday, Merkel said Europe needed to contribute to dealing with this global challenge.
"And for Europe, this means we of course need to, above all, protect our external borders across Europe - and protect them together - so that immigration to Europe is orderly," she said.
"But it also means we must take on more responsibility for countries where the causes for people to flee are, or where there are a lot of refugees, such as in Lebanon, Jordan or Turkey," Merkel added.
Many of those on the move are heading to Germany, which is Europe's largest economy and has relatively liberal asylum laws and a generous system of benefits.
A poll on Thursday showed Merkel's popularity slump to its lowest level in nearly four years, reflecting growing concern about the flood of migrants.
More than 200,000 people are estimated to have arrived in Germany in September alone -- roughly the same as for all of last year -- and the government estimates that 800,000 or more might come over the course of 2015.
In her podcast, Merkel said Germany needed to make clear that those who needed protection would get it but those who were only coming here for economic reasons would have to leave again.
"We need to be even more resolute about that and make that clear," she said.
She also said integrating the new arrivals was a "big task" and people should be able to express their concerns about it.
Merkel said Greece's external border with Turkey - a frontier that many migrants have crossed on perilous boat journeys - was an issue. Talks with Turkey were needed and in fact had already begun, she said.
It will also be necessary to provide more development aid and spend more on refugees via UN programmes, she added.
(The story has been refiled to fix typographical error in first paragraph.)