Diaz Arce made his debut for El Salvador in an April 1991 UNCAF Nations Cup qualification match against Nicaragua in which he scored two goals. Over his career, he earned a total of 68 caps, scoring a record 39 goals. He represented his country in 28 FIFA World Cup qualification matches and played at several UNCAF Nations Cups as well as at the 1996 and 1998 CONCACAF Gold Cups.