United Nations Secretary General Ban Ki-moon said he is "alarmed by the growing zenophobia" in Europe, and urged European countries to abide by "international humanitarian law and European law" in his speech to the Austrian lower house of parliament on Thursday.
Ban did not name any country, but his comments came a day after Austria passed some of Europe’s toughest asylum rules and announced plans to curb the flow of refugees by tightening border controls at the Alpine Brenner Pass with Italy.
Vienna is considering building a 400-metre border fence, on which building work began two weeks ago.
The secretary general said that the increasing "restrictive immigration and refugee policies… send a very negative message about the obligations of member states under international humanitarian law and European law."
"Divisiveness and marginalisation hurt individuals and undermine security."
Austria’s new legislation allows the government to declare a "state of emergency" if refugee numbers suddenly rise and reject most asylum seekers at the border, including those from war-torn countries like Syria.
Human Rights Watch criticised the law in a statement, saying it constitutes "a legal wall to asylum just as despicable as a razor-wire fence."
The UNHCR has said on Wednesday that the law "removes a centrepiece of refugee protection."
Italian Prime Minister Matteo Renzi also denounced Austria’s new refugee law.
Austria received 90,000 asylum request last year - the second highest number in the EU in proportion to a country's population after Sweden.
The number of asylum requests that can be granted each year has been limited to 37,500 by the new law.
Vienna’s centrist government, struggling to halt a surge in support for far-right groups by implementing the tougher asylum laws, has defended them by saying that other EU member countries don’t do their part, so it doesn’t have another choice.
The far right is rising in the polls ahead of Austria's presidential elections, with anti-immigrant candidate Norbert Hofer making it to the second round of elections which will be held on May 22.