WASHINGTON/Tehran  - President Donald Trump on Thursday said Iran was now formally “on notice” after a recent missile test, while also claiming the Islamic Republic was on the brink of collapse when it signed an international nuclear deal.

“Iran has been formally PUT ON NOTICE for firing a ballistic missile. Should have been thankful for the terrible deal the US made with them!” Trump tweeted, echoing similar comments by National Security Advisor Michael Flynn the day before. But there has been scant detail from the White House as to what the warning actually means in practical terms. It remains to be seen if the White House will push for sanctions this time around.

Flynn insisted that Sunday’s missile test was “in defiance of UN Security Council Resolution 2231,” which calls on Iran not to test missiles capable of delivering nuclear weapon. Iran’s ballistic missile program has been a bone of contention with the West since the nuclear deal took effect in January last year.

A previous, while controversial, test was not found to be in breach of the UN guidelines.

A senior Trump administration official said that it was clear the missile was capable of carrying a nuclear payload, while a second official said it was not considered a breach of the nuclear deal.

Both Trump and Flynn have been harsh critics of Tehran and vocal opponents of the nuclear deal with world powers that saw Iran curb its nuclear program in return for sanctions relief. “Iran was on its last legs and ready to collapse until the US came along and gave it a life-line in the form of the Iran Deal: $150 billion,” Trump said in a second pre-dawn tweet. He was referring to an estimate of the value of sanctions relief that Iran obtained from the White House - then under president Barack Obama - in exchange for signing the deal.

Meanwhile, Iran on Thursday rejected a warning from President Donald Trump over its latest missile test as unfounded and “provocative”, reflecting growing tensions between Tehran and the new US administration. Flynn insisted that the missile test was “in defiance of UN Security Council Resolution 2231,” which calls on Iran not to test missiles capable of delivering a nuclear weapon.

The remarks drew an angry response from Tehran. “Claims made by US President Donald Trump’s National Security Advisor are baseless, repetitive and provocative,” Iranian foreign ministry spokesman Bahram Ghasemi said, quoted by state news agency IRNA.

Iran has confirmed that it tested a ballistic missile, but denied that it violated the terms of the nuclear deal.

Tehran says its missiles do not breach UN resolutions because they are for defence purposes only and are not designed to carry nuclear warheads.

The row comes against a backdrop of already difficult relations over Trump’s travel ban on citizens from Iran and six other Muslim-majority countries.

The US warning prompted a defiant response from Iran’s elite Revolutionary Guards.

“The number of Iranian missiles, warships and defence missile launchers is growing every day, and the sky, land and sea is under the control of this nation,” said General Hossein Salami, the number two in the Guards which is in charge of weapons programmes.

“This is not a land where an outsider can set foot with sinister intentions,” he said. Iran has missiles with a range of up to 2,000 kilometres (1,250 miles), sufficient to reach Israel as well as US bases in the region.

There has been scant detail from the White House as to what its warning over the missile test means in practical terms, and it remains to be seen if Washington will push for new sanctions. Ghasemi said that the US warning came at a time when “the efforts by the Islamic Republic of Iran in fighting terrorist groups in the Middle East are known to all”. “It is regrettable that the US administration, instead of appreciating the nation of Iran for its continued fight against terrorism, is in practice aiding terrorist groups by repeating baseless claims and adopting unwise measures.”

He referred to Syrian rebel groups which “directly or indirectly receive financial, logistic and intelligence support by the US and its partners”.

Ghasemi dismissed charges of Iranian meddling in the region, saying Tehran wanted good relations with its neighbours based on “mutual respect and non-interference in countries’ domestic affairs.”