Esmail Kowsari told Hezbollah-affiliated Al Mayadeen TV that no decision on closing the Strait had been made but military preparations to do so were ready.
“Military measures concerning the Strait of Hormuz have been completed, but no decision has yet been made regarding its (closure) and the matter is still under review,” said Kowsari, a member of the parliament's national security committee.
The Strait of Hormuz is a waterway bordered by Iran, the United Arab Emirates, and Oman. Around a fifth of global oil and gas shipments pass through the strategic chokepoint, which was a site of conflict in the Iran-Iraq in the 1980s but was spared in the Mideast combat last month.
Tehran, Kowsari added, has not walked away from negotiations but US attacks on Iranian nuclear sites violated Iran's sovereignty and hurt diplomatic efforts.
Conditions for resuming talks do not currently exist, Kowsari said.
Iranian officials have repeatedly threatened to close the strait as tensions with Israel and the United States have flared in recent years.
Last month, Kowsari told state media that the Iranian parliament had approved a measure to close it but that the measure was not binding, and the final decision rests with Iran’s top decision-making body, the Supreme National Security Council.
A closure would likely upend global energy markets and risk triggering broader conflict.