Washington - 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 programme 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 programme 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: $150bn," 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.