PARIS (Reuters) - European Union countries should take advantage of a slowdown in the flow of migrants from Africa and the Middle East to devise a more coherent approach to a crisis that has strained relations between member states, the head of the OECD said on Friday.   In the first six months of 2017, the number of people landing on European shores reached 85,000, only about a tenth as many as at the peak of the migration crisis in the second half of 2015, according to data from the Organisation for Economic Co-operation and Development.  Right now we have an opportunity. There is a little bit of a breathing space,  Secretary General Angel Gurria said in an interview.  But I think we should use the opportunity of this quiet period to be able to have a better approach because, eventually, there are some 3.3 million refugees in Turkey and almost two million in Lebanon and Jordan. If they start moving, there is going to be a problem,  he said.   Citing the example of migrant arrivals from Libya, Gurria said Italy should not be left to carry the burden alone.    Italy cannot do this on their own (logistically). And they also cannot do it on their own financially,  Gurria said. Gurria, who has repeatedly highlighted the benefits of migration, said illegal immigrants who had come to the United States as children, the so-called  dreamers , were entitled to U.S citizenship. Last month, President Donald Trump s administration ended the Deferred Action for Childhood Arrivals policy (DACA), which began in 2012 under former U.S. president Barack Obama, and has been sending conflicting signals since about its future. The program has allowed nearly 800,000  dreamers  to work legally in the U.S without being deported.  These are American citizens,  Gurria said.   Some of them don t even speak the language of the country where they came from. They grew up in the U.S, went to school in the U.S,  he added.  Now, in many cases, because they are becoming adults, they will enrich the U.S. economy. We believe very strongly that this is where they belong.  