"Saudi Arabia cannot hide its crime of beheading a religious leader by severing political relations with Iran," Reuters quoted Rouhani as saying on Tuesday.
Meanwhile, Saudi Arabia insisted that the 47 people executed at the weekend had been granted "fair and just trials without any consideration to their intellectual, racial, or sectarian affiliation."
On Monday Russia offered to act as a mediator of the ongoing conflict.
Relations between Iran and Saudi Arabia soured following the execution Shia cleric Sheikh Nimr al-Nimr in Saudi Arabia, an outspoken critic of the Saudi monarchy, along with 46 other people convicted of terrorism.
Saudi Arabia cut ties with Iran on Sunday, responding to attacks by protesters on its diplomatic missions in the two most populous Iranian cities of Tehran and Mashhad.