The U.N.'s special investigator on Iran says the human rights situation in the country has deteriorated since Hassan Rouhani became president in 2013.

Ahmed Shaheed says "in my view the overall situation has worsened, as indicated by the surge in executions."

Shaheed told reporters in Geneva on Monday that 753 death sentences were carried out in Iran last year, compared with 580 in 2012.

He lamented that Iran executes more people per capita than any other country and that more than half of the death sentences were for drug-related crimes.

Shaheed says Iran has also introduced a number of laws putting pressure on dissidents, rights activists and journalists.

The U.N. expert said he hopes a resolution of its nuclear dispute with the West will improve the human rights situation, too.