Iran said it would examine "seriously and patiently" US allegations it planned to assassinate a Saudi ambassador.
Manssor Arbabsiar was held in the United States over a suspected plot to kill the Saudi ambassador.
The US has uncovered a plot by two Iranian men using a hitman to kill Saudi ambassador.
Day in Pics: 28th January
Showbiz World - January 28, 2015
President Barack Obama's speech at Siri Fort auditorium