Escalating a war of words with the United States, President Hassan Rouhani of Iran declared on Friday that his country would continue to develop new missiles and “would not seek anyone’s permission to defend our land.”
As he spoke at a military parade in Tehran, the Islamic Revolutionary Guards Corps unveiled a ballistic missile with a range of about 1,250 miles, making it capable of reaching much of the Middle East, including Israel.
Mr. Rouhani’s nationally televised speech at the parade — which commemorates the Iran-Iraq War of 1980-88 — and the show of force were a direct display of defiance toward President Trump, who signed a bill in August imposing mandatory penalties on those involved in Iran’s ballistic missile program and anyone who does business with them.
Although United Nations provisions seek to limit ballistic missile technology, the nuclear agreement negotiated in 2015 by Iran and six world powers, including the United States, does not prohibit Iran from developing such weapons.
The Trump administration has called the omission of ballistic missiles a central flaw of the agreement, which Mr. Trump may try to revisit — or scrap altogether, as he has threatened in the past.
At the annual United Nations gathering in New York this week, Mr. Trump called the nuclear deal “an embarrassment to the United States,” and Mr. Rouhani retorted, in his own address: “It will be a great pity if this agreement were to be destroyed by ‘rogue’ newcomers to the world of politics.”
Upon his return from New York, Mr. Rouhani strongly defended Iran’s right to self-defense.
“We will increase our military power as a deterrent,” he said. “We will strengthen our missile capabilities. We will not seek anyone’s permission to defend our land. Not only will we fortify our missiles, but our ground, navy and air forces will always be supported by the people.”
The unveiling of the new missile, called the Khoramshahr, comes two months after Iran launched a missile into space, prompting a new round of sanctions and criticism from the United States.
“Rouhani is playing hardball,” said Sanam Vakil, an Iran scholar at Chatham House, a think tank in London, and at the Paul H. Nitze School of Advanced International Studies at Johns Hopkins University. “By promising to step up Iran’s ballistic-missile program, Rouhani seeks to gain support from Iranian hard-liners who have long been critical of the nuclear deal, and who have repeatedly accused him of being soft in international relations. Moreover, hard-liners, such as Iran’s supreme leader, believe compromise with the United States is a futile exercise.”
She added: “History and the experience of other rogue states such as North Korea has also shown the Iranian government that it is only from a position of strength that regimes such as Iran’s can be protected.”
In his remarks, Mr. Rouhani said that Iran was ready to “defend the innocent people of Yemen, Syria and Palestine,” and would “strengthen our defensive and military power as much as we deem necessary for deterrence.”
The state-run news agency IRNA quoted the chief of the Revolutionary Guards’ airspace division, Gen. Amir Ali Hajizadeh, as saying that the new missile “can carry several warheads for various uses.” The agency did not provide further information on the missile.
Mr. Rouhani, a moderate, has staked his reputation on sealing the nuclear deal and relieving the Iranian economy of debilitating international sanctions. In a rejoinder to Mr. Trump’s call to renegotiate the nuclear deal, he said that “all countries” at the General Assembly meeting supported the nuclear deal, “except the United States and the Zionist regime,” a reference to Israel.
“Like North Korea, Iran is responding to Trump’s bellicosity by its own display of strength, to show it is not cowed,” said Mark Fitzpatrick, executive director of the Americas office of the International Institute for Strategic Studies, a British think tank.
He cautioned that Iran’s claim that the new missile could carry multiple warheads “needs to be taken with a grain of salt,” adding that the it “may mean nothing more than multiple cluster bombs,” not the kind of ballistic missile payload — multiple independently targetable reentry vehicle, or MIRV — associated with nuclear missiles.
Mr. Trump’s secretary of state, Rex W. Tillerson, has said that the Iran nuclear agreement must be changed or the United States would not stick with it. Iran has said the accord is not up for renegotiation.
The possibility that Washington might renege on the deal has worried some countries, especially as the world grapples with North Korea’s nuclear and ballistic missile development.
This week, Foreign minister Wang Yi of China said that tensions on the Korean Peninsula highlighted the importance of the Iranian deal, and Foreign Minister Sergey V. Lavrov of Russia said that the United States’ imposition of unilateral sanctions on Iran was “illegitimate and undermines the collective nature of international efforts.”