Hungary will hold a referendum on October 2 on EU plans to relocate migrants among member states, a scheme fiercely opposed by right-wing Prime Minister Viktor Orban, the president said Tuesday.

Hungary said Monday it had begun reinforcing its anti-migrant fence on the Serbian border following an increase in arrivals after the evacuation of Idomeni camp on the Greece-Macedonia frontier.

Last week, Greek officials moved some 8,400 people from the squalid, makeshift Idomeni encampment to reception centres elsewhere in the country.

Poland and Hungary have blasted Bill Clinton over a remark by the former U.S. president accusing the ex-communist EU and NATO countries of taking an authoritarian turn and wanting "Putin-like leadership".

"Poland and Hungary, two countries that would not be free but for the United States and the long Cold War have now decided that this democracy is too much trouble," Clinton said at an election rally last week for Democratic party presidential front-runner and spouse, Hillary Clinton.

Hungary and Poland on Wednesday slammed a European Union plan to fine member states that refuse to accept their quota of refugees, with Budapest calling it "blackmail" and Warsaw saying it sounded like an April Fool's joke.

The European Commission has proposed making EU countries pay a "solidarity contribution" of 250,000 ($290,000) euros per refugee they decline to take in as Europe struggles with its worst migration crisis since World War II.

The European Union has "sold out to Turkey" in its handling of the refugee crisis and the consequences are "impossible to predict," Hungary's prime minister warned in an interview published Saturday.

Viktor Orban launched the salvo in an interview with the German weekly Wirtschaftswoche as German Chancellor Angela Merkel and top EU leaders head to Turkey to boost a migrant deportation deal that has been slow to get off the ground.

Hungary's top diplomat on Friday said it was "not a fundamental human right" for migrants to pick their destination, during a meeting of EU members concerned about the record refugee crisis.

Foreign ministers and senior officials from 11 European Union nations plus Iceland met at the Latvian resort town of Jurmala to discuss Europe's worst refugee crisis since World War II, after a million migrants arrived on the continent's shores last year.

Hungary unveiled Thursday a draft package of anti-terror measures in response to the Brussels attacks that would make phone and Internet surveillance easier and allow bank accounts to be tracked in real time.

"The events in Paris and Brussels have settled the debate, the terrorism threat has grown," Interior Minister Sandor Pinter told a press conference in parliament.

Hungary is considering shutting its permanent refugee camps, officials said Friday, in yet another sign of the government's anti-migrant stance as the European Union tries to seal a deal with Turkey to stem the influx.

"The government has authorized Interior Minister Sandor Pinter to close the reception centers in Hungary, and it is now his duty to consider whether there is a need for them in the future," the office of Prime Minister Viktor Orban said in a statement.

The EU on Thursday questioned Hungary's decision to hold a referendum on mandatory quotas for refugees, which the bloc's leaders agreed on last year to deal with the migrant crisis.

"We fail to understand how it would fit into the decision-making progress agreed to by all EU member states under the treaties," European Commission spokeswoman Natasha Bertaud told a news briefing.

Hungary will hold a referendum on whether to accept mandatory EU quotas for migrants, Prime Minister Viktor Orban said Wednesday, protesting that Brussels has no right to "redraw Europe's cultural and religious identity."

"The government believes the decision about the mandatory relocation quota cannot be taken away from the Hungarian parliament," Orban told reporters, without disclosing a date for the nationwide ballot.