Iran tested a new medium-range ballistic missile last month in a breach of two UN Security Council resolutions, two US officials said on Monday.
The officials, both speaking on condition of anonymity, said the test was held on 21 November. One of them said the missile traveled within Iranian territory.
Fox News earlier on Monday on its website cited Western intelligence sources as saying the test was held near Chabahar, a port city near Iran's border with Pakistan.
All ballistic missile tests by Iran are banned under a 2010 Security Council resolution that remains valid until a nuclear deal between Iran and six world powers is implemented.
Under that deal, reached on July 14, most sanctions on Iran will be lifted in exchange for curbs on its nuclear program. According to a 20 July resolution endorsing that deal, Iran is still "called upon" to refrain from work on ballistic missiles designed to deliver nuclear weapons for up to eight years.
In October, the United States, Britain, France and Germany called for the Security Council's Iran sanctions committee to take action over a missile test by Tehran that month that they said violated UN sanctions. So far, no action has been taken by the committee.
Several Security Council diplomats said on Monday that they had received no official notification of a new alleged violation of the UN missile sanctions against Iran since the October notification. The diplomats spoke on condition of anonymity.