Hungary's prime minister is insisting that the country's constitution bans "Islamization" because the document aims to protect Hungarian language and culture.

Prime Minister Viktor Orban also says the constitution forces the government to oppose any kind of mass migration that would endanger those principles. He was speaking Monday in parliament at an event celebrating the fifth anniversary of Hungary's new constitution.

Orban says "to be clear and unequivocal, I can say that Islamization is constitutionally banned in Hungary."

Hungary has built razor-wire fences on its southern borders to stop migrants from passing through to other European nations. Orban has said he wants "zero" migrants in the East European nation.

Before the fences, nearly 400,000 migrants entered Hungary in 2015 on their way to richer nations in Western Europe.