text: Prime Minister Matteo Renzi said it was hard to seek EU help on migration "when some regions in your own country say the problem has nothing to with them".
  Leaders in Lombardy, Liguria and Veneto warn they cannot accept more migrants.
  Italy is struggling with a huge surge in migration, with nearly 6,000 people rescued from the sea just this weekend.
  More than 50,000 people have arrived in Italy this year, most of them setting sail from Libya aboard unsafe vessels.
  More than 1,500 people have drowned while making the Mediterranean crossing this year. The deaths have prompted an EU effort to boost naval patrols off Libyan waters.
  The rescued migrants are brought ashore to centres throughout Italy, where they are expected to remain until their claims for asylum within the EU have been processed.
  Speaking to reporters after the G7 summit in Germany, Mr Renzi said the EU had to acknowledge that its current system for dealing with migrants was not working.
  "What we need to do at the moment is solve problems, not by shouting but through action," he said.
  He also urged the EU to take in more refugees from Italy, saying a recent plan to relocate 24,000 refugees to other European countries was "not enough".
  The influx has put a severe strain on Italy's asylum infrastructure, and has fuelled support for right-wing politicians who oppose immigration.
  On Sunday, the president of Lombardy, Roberto Maroni, said his region would not take in any more migrants. He also threatened to cut funding for local authorities who continued to accept migrants.
  His stance was supported by Luca Zaia, the president of Veneto and a member of the Northern League. He was also backed by Giovanni Toti, the newly-elected president of the Liguria region and a member of Forza Italia.
  The three northern regions are among the most affluent in Italy, and have so far accommodated around 15% of the latest migrant influx.
  Sicily, a relatively poor southern region with high unemployment, has accommodated 22%.
  Italy's government predicts a total of 200,000 migrants will arrive on its shores this year, up from 170,000 in 2014.
target: Italy's government has criticised leaders in the north of the country for their refusal to host any more migrants rescued from the Mediterranean.