Iran's Foreign Ministry says possible new US sanctions will not change Tehran's nuclear policy, but could complicate talks with world powers.
Iran's state TV report on Thursday followed the US House's passage of tighter sanctions on Iran's oil sector, which is already under major pressure from Western economic measures seeking to rein in Iran's nuclear program.
The US plan now moves to the Senate.
Iranian state TV quotes Foreign Ministry spokesman Abbas Araghchi as saying sanctions will not stop the country's nuclear advance.
Araghchi claims the new American proposals could set back efforts at dialogue.
Iran and world powers seek to resume talks after Sunday's swearing-in of moderate President Hasan Rouhani, who has urged for more international outreach.
The West has been accusing Iran of seeking to develop nuclear arms. Tehran denies the accusation.
Meanwhile, Israel's Prime Minister Benjamin Netanyahu hailed the US sanctions on Iran's nuclear programme, approved ahead of the new Iranian president's inauguration.
"Following the Iranian elections the [US] House of Representatives has sent a clear message to the Iranian regime that international pressure will increase until Iran... ceases its pursuit of nuclear weapons capability," Netanyahu said in a statement.
Critics say the vote to pass stricter sanctions was badly timed, coming just three days before Rowhani, Iran's former nuclear negotiator, took the presidential helm.
Advocates of diplomacy have suggested that the United States should use the departure of Mahmoud Ahmadinejad as a chance to seek engagement with Iran, instead of maintaining a rigid posture.