The U.S. position was unclear before 2006 , but after that time the U.S. has taken the position that Iran does not have the right to uranium enrichment .
This activity is not specifically cited in the NPT .
The U.S. position was unclear before 2006 , but after that time the U.S. has taken the position that Iran does not have the right to uranium enrichment because this activity is not specifically cited in the NPT .