The United States is conducting a "serious review" into reports that Iran carried out a new round of ballistic missile testing in violation of UN resolutions, its United Nations envoy said Tuesday.

If reports of testing in November are confirmed, the United States will go before the UN Security Council "and seek appropriate action," Samantha Power told journalists.

"The US is conducting a serious review of the reported incident to see if we can confirm it," she said.

The United States, along with Britain, France and Germany, already asked a Security Council sanctions committee to investigate the October 10 test launch of a medium-range missile, calling it a serious violation, although Russia has questioned those claims.

The four countries maintained that the missile test violated a Security Council resolution adopted in 2010 to prohibit Tehran from conducting launches of ballistic missiles capable of delivering nuclear weapons.

"It is extremely important that the Security Council resolutions be enforced," Powers said.

Tehran says its missiles are not designed for nuclear capability and therefore not in violation of the resolutions.

The four countries took part along with China and Russia in successful negotiations to reach a historic deal with Iran in July that calls for lifting sanctions in exchange for curbs on Tehran's nuclear program.

Iran insists it has no plans to develop atomic weapons.