A senior Iranian official said Sunday it was "shameful" that U.S. President Donald Trump had named John Bolton as national security adviser because of his ties with rebels whom Iran sees as "terrorists," the state news agency IRNA reported.

Commentators said last week when Bolton was named that it signaled a toughening of Washington's stance on Tehran and another nail in the coffin of the Obama-era agreement between Iran and world powers to limit Tehran's nuclear ambitions, already cast into doubt by Trump himself.

"For a seemingly superpower country, it is shameful that its national security official would be receiving a salary from a terrorist sect," IRNA quoted Ali Shamkhani, secretary of Iran's Supreme National Security Council, as saying.