Republican presidential candidate Donald Trump campaigns in Kiawah Island, South Carolina.

The Republican race for the party's 2016 presidential nomination erupted into a four-candidate crossfire on Wednesday over who has the proper experience and is the most conservative, days before South Carolina voters put their stamp on the campaign.

Donald Trump, who has argued his experience negotiating tough real estate deals makes him best qualified to be U.S. president, said on Wednesday it might be impossible to forge a lasting peace agreement between the Israelis and the Palestinians.

U.S. Democratic presidential candidate Hillary Clinton courted the critical black vote on Tuesday as she met with civil rights leaders in New York and promised in a speech to tackle "very real barriers" confronting African-Americans.

The German government expects 500,000 refugees to come to Germany this year, German newspaper Rheinische Post cited sources from the Federal Labor Office as saying.

Demand has never been higher for the services of Turkish smuggler Dursun, who has taken migrants to Europe for more than decade, and he says nothing short of an army could stamp out his illicit trade.

France, Germany, other EU nations and Turkey are expected to meet before an EU summit in Brussels on Thursday to discuss the migration crisis that is worsening due to a growing number of people fleeing air strikes in Syria.

Hungarian Prime Minister Viktor Orban said on Monday that the European Union's policy on the migration crisis had failed and underlined that Hungary would not accept a distribution of refugees by national quota.

About two out of three Czechs oppose taking in refugees from war zones, according to an opinion poll published on Monday, reflecting growing anti-migrant sentiment in a country that has taken a tough stance on migrants and refugees.

Central European leaders are ready to help Balkan countries seal their borders with Greece to stem the flow of migrants across the continent, Czech Prime Minister Bohuslav Sobotka told Reuters on Sunday.