"The situation prevailing in Syria today and the death of a certan number of innocent people caused by chemical weapons is very distressing," said Rowhani, adding that Iran, itself a victim of chemical attacks in its 1980-1988 war with Iraq, "totally and vigorously condemned the use of chemical weapons".
His comments came as a top UN official was to visit Syria Saturday for talks as demands grew for a prompt probe into opposition claims the regime unleashed a chemical attack.
US President Barack Obama said the alleged use of chemical weapons was "a big event of grave concern," while Russia hit out at calls for force against its ally Syria.
US Defense Secretary Chuck Hagel strongly suggested the Pentagon was moving forces into place ahead of possible military action against Syria, even as Obama voiced caution.
