The United Nations human rights watchdog says it is "shocked" by a Hungarian government questionnaire which links migration with terrorism and fears it could bolster anti-immigration sentiments.

The office of the U.N. High Commissioner for Human Rights said Friday in a statement that some of the questions in the "national consultation" being sent out to Hungarian voters "actively promote hostility toward migrants and risk spreading xenophobia within the country."

Prime Minister Viktor Orban wants the European Union to give individual countries more power to set their own immigration policies and says Hungary does not want economic immigrants.

Since late 2014, Hungary has seen a huge rise in the number of migrants arriving through its southern border with Serbia. Most quickly move further west to Austria or Germany.