TEHRAN: Iranian President Hassan Rouhani on Sunday demanded the his United States (US) counterpart Barack Obama to block the extension of sanctions passed by the Congress, saying Tehran would otherwise ‘firmly respond’. Rouhani denounced the legislation passed by the US Congress to extend the Iran Sanctions Act (ISA) for 10 years as a violation of Tehran’s nuclear deal – which curbs Iran’s nuclear programme in return for the lifting of international financial sanctions. “America’s president is obliged to exercise his authority by preventing its approval and particularly its implementation and if this gross violation is carried out we will firmly respond,” Rouhani said in a speech to the parliament – which was carried live by state television. President Obama is expected to sign the legislation into law, the White House said on Friday – causing a blow to Rouhani’s diplomatic opening to the West that led to the nuclear deal.