Iran's defence minister on Monday denied that Iranian forces have tested a medium-range missile with improved accuracy compared to its predecessors.
"We have not conducted such a test," said Hussein Dehghan, according to the ISNA news agency.
His comments followed a statement by an unidentified high-ranking military official quoted by the Tasnim news agency as saying a rocket with a range of 2,000 kilometres had been tested two weeks ago.
Details on Iran's weapons tests cannot normally be verified as they take place without independent observers.
The tests underscore ongoing fears in the West that Iran could launch one of its Shahab-3 models, which supposedly have a 2,000-kilometre range, in a missile attack on its archenemy, Israel.
President Hassan Rowhani has insisted that Iran has no intention of using the rockets against neighbouring countries and that they serve only defence purposes. All factions in Iran view them as legitimate, even necessary, in light f the military threat posted by Israeal and the United States.
In Washington, the US State Department said that the claimed launch, if accurate, would be "inconsistent" with a United Nations resolution on Iranian missile programmes. In the past, the United States has gone to the UN Security Council seeking action after similar Iranian launches, to no avail.
"If this launch is confirmed, we will do so again," State Department spokeswoman Elizabeth Trudeau said.
While concerns over Tehran's intentions had abated since the implementation of a nuclear agreement with the West in January, tensions once again rose after Iran tested ballistic missiles in March, two of which carried anti-Israeli inscriptions.