Iran tested a ballistic missile last month, a US official has said, describing the second such test since the nuclear agreement in July. The State Department said it was conducting a "serious review" of such reports.
The test occurred Nov 21, according to the official, coming after an Oct 10 test that Iran confirmed at the time.
The official said yesterday other undeclared tests occurred earlier than that, but declined to elaborate. The official wasn't authorised to speak on the matter and demanded anonymity.
Ballistic missiles are especially sensitive with Iran because they could provide the delivery system for a nuclear warhead. As part of nuclear negotiations with world powers, Iran accepted an eight-year extension of a UN ban on its ballistic missile program.
The November test was first reported by Fox News, which said a mid-range missile with a range of 1,200 miles (1,930 kilometres) was launched from a known site near the Gulf of Oman.
The test may reflect an effort by Iranian hardliners to derail the nuclear pact, coming on top of the recent arrests of an American citizen and US resident and reports that Washington Post reporter Jason Rezaian was sentenced to an unspecified prison term following an espionage conviction.
According to the official, the US assesses that hardliners opposing the nuclear deal struck by Iran's moderate President Hassan Rouhani may be trying to provoke the United States into authorising new sanctions against Iran and raising tensions between Washington and Tehran.
Top Iranian officials have vowed to respond to any new forms of economic pressure from the West.
State Department spokesman John Kirby refused to confirm the test. "We're conducting a serious review of this reported incident," Kirby told reporters. He added, "If the reports are confirmed and if there is a violation of any relevant UN Security Council resolution, then we're going to take the appropriations actions."
He stressed that ballistic missile activity wasn't a violation of the July deal that imposed more than a decade of restrictions on Iran's nuclear program in exchange for hundreds of billions of dollars in potential relief from international sanctions.
He said the US would monitor Tehran for "destabilising" behaviour, and that is "why we have a robust military presence in the region, and it's why we still have and will remain capable of having unilateral sanctions."
After the October test, President Barack Obama noted that Iran has often violated missile prohibitions. He said the US would make clear to Iran that there are costs for bad behaviour, but stressed that the issue was separate from nuclear arms control.
On Nov 24, the US, Britain and France pressed Iran for a formal explanation at the United Nations.
