BERLIN (AP) — U.N. chief Ban Ki-moon says building barriers won't solve the migrant crisis in Europe.

The United Nations secretary-general told German daily Bild in an interview published Friday that "building walls, discriminating against people or sending them back is no answer to the problem."

Ban praised German Chancellor Angela Merkel's "human political leadership" in dealing with the migrant crisis and urged other politicians to follow her example.

He declined to comment on speculation that Merkel might be nominated to succeed him in the top U.N. role when his second term ends on Dec. 31.