The US has imposed new sanctions on Iran over its missile and military-related activities in the Middle East hours after it maintained the international nuclear agreement with Tehran, a report said.

The US is imposing sanctions on 18 Iranian individuals and entities over their suspected support to Iran's ballistic missile programme and Iranian revolutionary guard, the State Department declared on Tuesday, reported Wam, the Emirates official news agency.

In a daily briefing, State Department spokeswoman Heather Nauert stated the US was still "deeply" concerned about "Iran's malign activities across the Middle East, which is undermining regional stability, security, and prosperity."

The US state department went on to say that Iran had continued its support to the Syrian regime, despite the atrocities committed by Bashar al-Assad against his people, and to the Houthi rebels in Yemen by providing them with advanced weapons, who were threatening navigation in the Red Sea and attacking the Kingdom of Saudi Arabia, thus prolonging the struggle in Yemen.

The US spokesperson mentioned that Iran's continued support to terrorist groups, including Hezbollah and Hamas, would threaten the stability in the Middle East.

She noted that Iran continued to test and develop ballistic missiles, in defiance of the UN Security Council resolution No. 2231. Iran's support to heinous activities threatens "positive contributions" towards regional and international peace and security, she added.

"The administration is continuing to conduct a full review of the US policy towards Iran, including reconsidering the nuclear agreement, as well as the threats posed by Tehran to world security," Nauert remarked.