The U.N. chief is warning that the values of tolerance and understanding are facing profound tests around the world.

Secretary-General Ban Ki-moon said in message commemorating the U.N.'s International Day of Tolerance on Wednesday that from sectarian armed conflicts to politicians who sow division to gain votes, the values enshrined in the Universal Declaration of Human Rights are under threat.

"Day by day, bigotry shows its face through racism, anti-Muslim hatred, anti-Semitism and other forms of discrimination," Ban said.

"The United Nations promotes tolerance as a matter of its fundamental identity. When tolerance is upheld, we encourage the world to emulate those fine examples. When tolerance is threatened, we must speak out," Ban added.