A long-range ballistic surface-to-surface missile is fired by the Iranian Revolutionary Guard Corp in Iran (Omid Vahabzadeh/Fars News Agency via AP)

Iranian officials said Thursday that the Islamic Republic would continue its missile program and said a series of tests it conducted this week do not violate United Nations prohibitions.

Brig. Gen. Amir Ali Hajizadeh, a senior commander for the Iranian Revolutionary Guard Corps that runs Iran’s missile program, told state television that it has more missiles ready to launch, and they are for defensive purposes.

“Iran’s missile program will not stop under any circumstances,” Hajizadeh said. “We are always ready to defend the country against any aggressor.”

Foreign Ministry spokesman Hossein Jaberi Ansari said the missiles were conventional weapons, not designed to carry nuclear warheads, the state-run Islamic Republic News Agency said.

“The Islamic Republic of Iran will not compromise over its security and defensive power,” he said, and will “continue its completely defensive and legitimate missile program.”

An Iranian television news broadcast shows testing of two missiles that Tehran says are "capable of reaching Israel." (Reuters)

On Wednesday, the Revolutionary Guards fired two ballistic missiles, including one with graffiti saying “Israel should be wiped off the earth” written in Hebrew on it. Iranian officials said workers scribbled the words on the missile before its launch.

The Iranian tests have been criticized in Congress and prompted renewed calls for more sanctions against the country.

“Iran sees it can violate U.N. missile sanctions with no consequence, it will violate this nuclear deal too,” said House Foreign Affairs Committee Chairman Edward R. Royce (R-Calif.).

[Biden: Iran under close watch amid reports of missile tests]

The State Department said it does not consider the missile tests a violation of the landmark nuclear agreement reached last year, which lifted international sanctions against Iran in exchange for scaling back its nuclear program. The agreement does not explicitly address missiles.

There had been a ban on missile testing, but it was lifted by the U.N. Security Council after the deal was finalized. In its place came a new resolution that “calls upon Iran not to undertake any activity related to ballistic missiles designed to be capable of delivering nuclear weapons, including launches using such ballistic missile technology.”

The resolution’s language allows Iran to argue its ballistic missiles are not “designed” to carry nuclear warheads, said Kelsey Davenport, director of nonproliferation policy at the Arms Control Association. But the missiles exceed the standard range and weight internationally accepted as the definition for a nuclear capable missile — anything with a payload over 500 kilograms and a range of more than 300 kilometers. According to Hajizadeh, some of the missiles carried 24 warheads and one ton of TNT.

“Tehran would be hard-pressed to prove that the missiles can only carry conventional payloads,” Davenport said. “Washington has a case for claiming a violation of the Security Council resolution.”

Secretary of State John F. Kerry, who negotiated the nuclear deal, expressed his “concerns” over the missile launches in communications with Iranian Foreign Minister Mohammad Javad Zarif, said State Department deputy spokesman Mark Toner on Thursday.

The United States has not confirmed the missile tests yet, Toner said, but if confirmed, Washington will take its concerns to the Security Council.

U.N. Secretary General Ban Ki-moon urged “restraint,” said his spokesman, Stéphane Dujarric.

“In the current political atmosphere in the Middle East region, and so soon after the positive news of the lifting of sanctions against Iran, the secretary general calls on the government of the Islamic Republic of Iran to act with moderation, caution and the good sense not to increase tensions through any hasty actions,” Dujarric said.