Parliament Speaker Ali Larijani said Iran should respond to a fresh US bid to pressure Tehran into making further concessions after the conclusion of landmark nuclear talks.
"Signs emerging over the past few months show that the Americans are trying to exert pressure through other channels on Iran," he told a Majlis session Sunday, Press TV reported.
The session was attended by Foreign Minister Mohammad Javad Zarif who led the Iranian delegation to the talks with major powers, culminating in an agreement in July 2015.
Larijani commended Zarif and his team of negotiators for their efforts "which were successful for the most part" in "safeguarding the rights of the Iranian nation" during the "complex, difficult and multifaceted negotiations."
Zarif had gone to the Majlis to brief the new MPs on the outcome of the nuclear agreement and its implementation amid worries about the commitment and good faith of the opposite side.
"The Majlis, the administration and the supervisory council on implementation of the Joint Comprehensive Plan of Action [the official title of the nuclear deal] should be vigilant and resist the excessive demands of the Americans and other countries," the speaker said.
Moves to Undermine Deal
"The Americans regularly [seek to] approve measures in Congress and use pressure tactics to create loopholes in the framework and regulations of the JCPOA," he noted.
The deal with the world powers calls for the removal of all nuclear sanctions on Iran in return for scaling back of its disputed activities.
Since the conclusion of the agreement, several American lawmakers have been pushing for legislation to impose new sanctions on Iran if necessary over its ballistic missile tests.
The hawkish senator Bob Corker has said he is working on legislation that he hopes will attract strong bipartisan support. That measure has not yet been unveiled and aides say they have no more information about when it might be introduced.
Republican Senator Kelly Ayotte and 18 other senators from her party have introduced a separate bill that would extend the Iran Sanctions Act through 2031 and require new sanctions over Iran's missile tests.
The act, which imposed nuclear, missile and terrorism sanctions on Iran, expires at the end of 2016, and both Democrats and Republicans in Congress support extending it.
Iranian lawmakers have passed a bill which calls for retaliatory measures if new sanctions are imposed. "According to the Majlis bill, if westerners concoct sanctions in other aspects, Iran has to take counter-measures," Larijani told the chamber but did not specify what the new measures would be.
