Washington believes the rocket technology can potentially be used to build ballistic missiles.
US: Iran's space rocket breaches UN resolution
US-Iran relations: Divergences
The United States and Iran have had troubled diplomatic relations since the 1979 Islamic Revolution.
Currently there are four primary areas of contention between Iran and the US: US perceptions of Iran's nuclear programme, US perceptions of Iran's support to terrorism, Iran's perceived role in the Israel-Palestine conflict and the regional peace process & alleged human rights abuses in Iran.
US had slapped sanctions on Iran over missile program
US State Department spokeswoman Nauert said the US considers the rocker-launch "to be [Iran's] continued ballistic missile development."
She said the rocket-launch was a "provocative action" that violated the "spirit" of the nuclear deal.
Earlier this month, Washington imposed fresh economic-sanctions on Iran over its ballistic missile program.
It said Iran's "malign activities" in the Middle East undercut any "positive contributions" of the deal.
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UN Security Council resolution bars Iran from missile testing
Nauert said the rocket launch violated UNSC Resolution 2231.
The resolution endorsed the 2015 Iran nuclear deal and called on Tehran not to undertake activities pertaining to nuclear-capable ballistic missiles, including launches related to such technology.
The resolution stops short of explicitly banning such activity.
Iran has denied having missiles capable of using ballistic missiles.
Pentagon believes space rocket could be reconfigured into ICBM
Scott Kripowicz, a senior official with the Pentagon's Missile Defense Agency said Iran's space rockets involving "multi-stage systems that further the development of technologies for intercontinental ballistic missiles (ICBM) are becoming a more realistic threat."
He said space-launch vehicles use similar technologies as ICBMs and can be configured to become missiles.
Iran insists its space program is peaceful.
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