EU president Donald Tusk on Tuesday urged a crackdown on the "murderers" among human traffickers who have killed scores of people trying to reach Europe from conflicts abroad.

"We have to focus on rescuing people's lives and... the fight against human traffickers and smugglers," Tusk said ahead of a meeting with Israeli President Reuven Rivlin.

"In fact we can talk today about murderers because they are directly responsible for the death of thousands of people. Maybe this is the most important thing today."

Tusk added that "in this dramatic crisis we talk also about the wider context. It is about economy, it is about security -- not only the security of European borders but also the situation in some countries in your region."

The crisis also touched on "social phenomena like xenophobia, for example," Tusk said, with the arrival of the migrants and refugees, many of them from war-torn Syria, provoking harsh reactions in some European nations.

Tusk had earlier warned in Brussels that the human haemorrhage to Europe would be long-lasting, calling it "the beginning of a real exodus, which means that we will have to deal with this problem for many years to come."

There has been a deep division within the EU about how to respond to the crisis, with former Communist-ruled members of the 28-nation bloc, such as Hungary, taking a hardline approach.

European Commission chief Jean-Claude Juncker was expected Wednesday to unveil a plan to relocate 120,000 migrants from frontline states.

Germany would take more than 31,000 migrants, France 24,000 and Spain almost 15,000, a source told AFP. Separately, British Prime Minister David Cameron said Britain could take 20,000 over five years.

Meanwhile, the poor and desperate kept coming, both on the land corridor through Turkey and the Balkans and on overcrowded boats in the Mediterranean on journeys that have left 2,800 dead or missing this year.

At the start of a meeting with Tusk on Tuesday evening, Israeli Prime Minister Benjamin Netanyahu said that due to "militant Islam" Europe was facing a "tsunami of people fleeing from the worst crimes that humanity has seen since the Holocaust."

Netanyahu, who met Italian Prime Minister Matteo Renzi in Florence last month, said they had discussed prospects of joint projects in Africa to help stem the flow.

Netanyahu said they talked about "the possibility of cooperating in sub-Saharan Africa with Italy, but also with other European countries, to deal with the problem at the source."

"To strengthen African governments in agriculture, in the economy, in communications, in security, in energy, to prevent the collapse of those societies and the suffering that accompanies the people who are seeking to flee for their lives to Europe."