Iran said yesterday it had successfully tested a new medium-range ballistic missile with a range of 2,000 km (1,200 miles) in defiance of US pressure to halt its advanced weapons programme. The launch came shortly after the US President attacked the 2015 Iran nuclear deal in a speech at the UN in New York and will further increase political tensions between the two countries.

The State broadcaster IRIB carried footage of the Khoramshahr missile without giving its time and location. It included video from an on-board camera which it said showed the detachment of the cone that carries multiple warheads.

"The weight of the Khorramshahr missile's warhead has been announced to be 1,800 kg (4,000 lbs), ... making it Iran's most powerful missile for defence and retaliation against any aggressive enemy," state television said.

The US has imposed unilateral sanctions on Iran, saying its missile tests violate a UN resolution which calls on Tehran not to undertake activities related to technology capable of delivering nuclear weapons. Iran denies any such plans.

The missile was first displayed at a military parade on Friday, where President Hassan Rouhani said Iran would strengthen its missile capabilities. With its range, the missile is capable of reaching much of the Middle East, including Israel, and was, according to Mr Rouhani, being developed “as a deterrent”.

Iran's Defence Minister, Gen Amir Hatami, outlined the missile's specifications. "The ability to evade the enemy's air defence line and to be guided from the moment of launch until the target is hit turns Khoramshahr into a tactical missile," he said. Iran would "not seek permission from any country for producing various kinds of missile", he added.

Britain voiced concerns about the latest test with the Foreign Secretary Boris Johnson writing on Twitter: "Extremely concerned by reports of Iran missile test, which is inconsistent with UN resolution 2231. Call on Iran to halt provocative acts."

The US announced fresh sanctions on Iran in July over its ballistic missile programme and what it claimed was the country's support for terror organisations. It also imposed sanctions on Iran after a ballistic missile test in January, saying such launches violate the spirit of the 2015 agreement between Iran and six world powers to limit its nuclear programme in exchange for sanctions relief.

Mr Trump included Iran among a “small group of rogue regimes”, and said its government was bent on “death and destruction”, adding that a nuclear agreement was an “embarrassment” to the US.