Foreign Ministry spokesperson Marzieh Afkham said under international law, governments have to adhere to their international commitments.
She made the remarks in a press conference on Wednesday, IRNA reported.
Iran is holding nuclear talks with governments, so the US government is bound to meet commitments under a final agreement, she noted.
The US Senate Foreign Relations Committee on Tuesday unanimously approved a bill that would require the US administration to submit a final nuclear deal with Iran to Congress so that the lawmakers review the agreement and vote to approve or disapprove it.
The bill, which is considered to be a compromise between the White House and Congress as it was modified by amendments proposed by Democratic lawmakers to make it more palatable to the administration, is expected to pass the full Senate and the House of Representatives.
Elsewhere, Afkham said a new round of nuclear talks at the level of political directors and experts will be held on Wednesday at a venue yet to be decided, adding that nuclear discussions will also be held on the sidelines of 2015 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, which starts at UN Headquarters in New York on April 27, in view of the presence of Foreign Minister Mohammad Javad Zarif at the event.
Commenting on cooperation between Iran and the International Atomic Energy Agency, she said the cooperation is on a "good path".
She went on to say that most of the 18 questions raised by the IAEA have been answered and the agency has reached to the conclusion that there is no "diversion" in Iran's nuclear activities.
In addition, Afkham stated that Iran and Russia have "comprehensive" relations in various political, economic and security areas.
The relations in the area of defense have been affected by sanctions and the dispute over the delivery of S-300 missile systems, she said.
The foreign ministry official added that the systems are due to be delivered to Iran as the Kremlin decided to lift the ban on the delivery of the defense systems.
