Iran's influential parliament speaker hit out at Washington Wednesday, accusing it of disrupting implementation of last year's landmark nuclear deal and failing in the fight against the Islamic State group.
Ali Larijani, a conservative who helped the nuclear deal pass in parliament last year, warned that Washington risked forcing Tehran into a path of renewed confrontation by putting obstacles in the way of its promised readmittance to the world economy.
"With great sadness, parliament... warns the US administration, House of Representatives and Senate that the efforts to undermine the nuclear agreement have reached a point that leaves no option for Iran but confrontation," he said.
Larjiani said the West had failed to give Iran sufficient recognition for its contribution to the fight against IS and hit out at the United Nations for continuing sanctions against its foreign operations commander.
Larijani said Western governments should be "thankful to Iran and (its elite Revolutionary Guard foreign operations unit) the Quds Force who have helped Iraq against the bestial terrorists" of IS.
"You, who neither have the courage to confront Daesh (IS), nor know how to fight it, as they carry out bloody attacks in three European countries... how dare you call the admirable Quds Force's fight a violation?" he asked.
The Quds Force and its commander Major General Qassem Suleimani remain under UN sanctions over its involvement in Iran's ballistic missile programme, which was not covered by last year's nuclear deal.
The sanctions include a travel ban and a recent visit to Baghdad by Suleimani was criticised by UN chief Ban Ki-moon in his latest six-monthly report on implementation of the sanctions.
Long a shadowy figure, Suleimani has become the public face of Iran's intervention against IS in Iraq and Syria, making repeated televised appearances from the front lines.
Iran is not part of the US-led coalition fighting the jihadists but has played a major military role in both countries.