RIYADH, May 21 (Reuters) - Muslim-majority countries must take the lead in combating radicalization, U.S. President Donald Trump said in a speech to leaders from 55 Muslim countries in Saudi Arabia on Sunday.

He also said that Arab nations had suffered the deadliest toll of "fanatical violence" and that there was a humanitarian and security disaster that was spreading in the region. (Reporting by Jeff Mason; Editing by Alison Williams)