The United States on Thursday called Iran's missile program a "serious threat" after Tehran unveiled a new model with its longest range to date.

Earlier, the Iranian armed forces unveiled in a ceremony their latest model of ballistic missiles dubbed the Khorramshahr-4 long-range strategic missile.

"Iran's development, and proliferation of, ballistic missiles poses a serious threat to regional and international security and remains a significant non-proliferation challenge," State Department Spokesperson Matthew Miller told reporters.

The Iranian Defense Ministry highlighted that the Khorramshahr-4 missile will have a range of 2,000 kilometers (1,242 miles) and be able to carry warheads weighing over one tonne.

"An Iran with a nuclear weapon would likely act even more provocatively, and that's why we are so committed to preventing Iran from acquiring nuclear weapons," Miller indicated.

On her part, French Foreign Ministry Spokesperson Anne-Claire Legendre claimed the Iranian move was a violation of the UN resolution 2231 that endorsed the 2015 nuclear deal.

"These activities are all the more worrying in the context of the continuing escalation of Iran‘s nuclear program," Legendre said.

Earlier, Iran's representative at the UN reiterated in a statement that "Iran's missile program is designed based on conventional defense capability, and none of Iran's ballistic missiles are designed to carry nuclear warheads, and Iran has never sought to acquire nuclear weapons and nor will it in the future."

In the same context, Israeli media reported that Tehran's unveiling of its latest model of ballistic missiles came days after Israeli occupation Chief of Staff Herzi Halevi and other top military officials warned of a possible war with Iran over its nuclear program.

The Times of "Israel" noted that the Khorramshahr-4 missile can reach "Israel" and US bases in the Middle East.

Israeli media also suggested that the unveiling of the new Iranian missile and its timing is part of Iran's deterrence theory, which aims to deter "Israel" and its threats.

The Israeli Channel 12 questioned Tehran's announcement and its timing.