US cyber attacks against Iranian targets have not been successful, Iran's telecoms minister has said.

The announcement came within days of reports that the Pentagon had launched a long-planned cyber attack to disable Iran's rocket launch systems.

Tension is running high between lran and the US after President Trump said he called off a military strike to retaliate for Iran's downing of an unmanned US military drone.

On Thursday, the Pentagon launched a long-planned cyber attack, Yahoo News said, citing former intelligence officials. The cyber strike disabled Iranian rocket launch systems, the Washington Post said on Saturday.

"They try hard, but have not carried out a successful attack," Mohammad Javad Azari Jahromi, Iran's minister for information and communications technology, wrote on Twitter.

Tensions high as Trump approves new Iran sanctions: In pictures Show all 17 1 /17 Tensions high as Trump approves new Iran sanctions: In pictures Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, their surface-to-air missile is seen as it shoots down a US surveillance drone EPA Tensions high as Trump approves new Iran sanctions: In pictures This photo shows US RQ-4A Global Hawk unmanned surveillance drone. A drone of this model was shot down by Iran on Thursday 21 June AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures An oil tanker is on fire after it was subject to a suspected attacked at the Gulf of Oman on June 13. The US has blamed Iran for the attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures US President Trump holds up a signed executive order to increase sanctions on Iran on 24 June AP Tensions high as Trump approves new Iran sanctions: In pictures Iranian President Rouhani stated in a televised address that the White House is "afflicted by mental retardation" following the increase in sanctions on 25 June EPA Tensions high as Trump approves new Iran sanctions: In pictures An Iranian navy boat tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures A screenshot from a video released by the US Department of Defense that the US claims to show Iranian removing an unexploded limpet mine form the hull of the Japan-owned ship that was attacked in the Gulf of Oman on June 13 Getty Tensions high as Trump approves new Iran sanctions: In pictures An item reportedly found on the Japan-owned oil tanker that was attacked on June 13 in the Gulf of Oman AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures A handout photograph from the US Department of Defense shows a composite material that the US claim was left behind on the hull of the Japan-owned oil tanker following the removal of an unexploded limpet mine Getty Tensions high as Trump approves new Iran sanctions: In pictures A view from the cabin of an Iranian navy boat as it tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack EPA Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The picture suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The pictures suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack EPA

"Media asked if the claimed cyber attacks against Iran are true," he said. "Last year we neutralised 33 million attacks with the (national) firewall."

Azari Jahromi called attacks on Iranian computer networks "cyber-terrorism", referring to Stuxnet, the first publicly known example of a virus used to attack industrial machinery, which targeted Iran's nuclear facilities in November 2007.

Stuxnet, widely believed to have been developed by the US and Israel, was discovered in 2010 after it was used to attack a uranium enrichment facility in the Iranian city of Natanz.

The US has also accused Iran of stepping up cyber attacks.

Last year, Mr Trump withdrew the US from a 2015 accord between Iran and world powers that curbed its nuclear programme in exchange for easing sanctions. Relations in the region have worsened significantly since then.

Mr Trump said on Sunday he was not seeking war with Iran and would be prepared to seek a deal to bolster its flagging economy.

An Iranian navy commander described the shooting down of the US drone as a "firm response" to the US and warned it could be repeated.

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"Everyone saw the downing of the unmanned drone," navy commander Rear Admiral Hossein Khanzadi told the Tasnim news agency.

"I can assure you that this firm response can be repeated, and the enemy knows it."