U.S. Secretary of State Mike Pompeo on Saturday condemned what he described as Iran's testing of a medium-range ballistic missile capable of carrying multiple warheads, saying the test was a violation of the international agreement on Tehran's nuclear program.
Amid mounting tensions between Washington and Tehran over ballistic missiles and other points of contention, Pompeo warned in a statement that Iran is increasing its "testing and proliferation" of missiles and called on the Islamic republic to "cease these activities."
Earlier this year, U.S. President Donald Trump pulled out of an international nuclear agreement, reached by his predecessor Barack Obama, and reimposed sanctions on Tehran. Trump fiercely criticized the deal for not including curbs on Iran's development of ballistic missiles or its support for proxies in Syria, Yemen, Lebanon and Iraq.
Iran says its missile program is purely defensive but has threatened to disrupt oil shipments through the Strait of Hormuz in the Gulf, if the U.S. tries to strangle Iranian oil exports. Last month, an Iranian Revolutionary Guards commander said U.S. bases in Afghanistan, the UAE and Qatar, as well as U.S. aircraft carriers in the Gulf, were within missile range.
Pompeo's statement, issued on Twitter, provided few details about the latest Iranian missile wwww.
"The Iranian regime has just test-fired a medium range ballistic missile that's capable of carrying multiple warheads," he wrote in the tweet.
"This test violates UNSCR 2231," he added, citing the United Nations Security Council's endorsement of the international nuclear agreement.
"We condemn this act," he concluded.
U.S. Defense Secretary Jim Mattis, addressing a security forum in California, said the Iranian launch was significant and was a reminder that Tehran was unlikely to be deterred from pursuing missile technology or supporting militant proxies.
"It shows that our best efforts to try to talk them out of their aggressive support of terrorism is probably going to be as unsuccessful as the U.N.'s effort to stop them from launching missiles," Mattis said.
He added that while the strategic threat from Iran was less significant globally than the one from North Korea, it was still regionally significant.
"And it could grow beyond that if it's not dealt with," Mattis said.
The regime in Tehran has ruled out negotiations with Washington over its military capabilities, particularly its missile program, which is run by the country's Revolutionary Guards Corps.
On Tuesday, the head of the Atomic Energy Organization of Iran warned the European Union that Tehran's patience was running out on the bloc's pledge to keep up oil trading despite U.S. sanctions. He said Iran could resume enriching uranium to 20% purity if it fails to see economic benefits from the 2015 deal that curbed its nuclear project.
Meanwhile, on Saturday, Iran's navy launched a domestically made destroyer, which state media said has radar-evading stealth properties.

In a ceremony broadcast live on state television, the 1,300-ton Sahand destroyer – which can sail on voyages lasting five months without resupply – joined Iran's regular navy at a base in Bandar Abbas in the Persian Gulf.
The Sahand has a helicopter landing pad, is 96 meters (105 yards) long and can cruise at 25 knots. It is armed with surface-to-surface and surface-to-air missiles as well as anti-aircraft batteries and sophisticated radar and radar-evading capabilities, the report said.
"This vessel is the result of daring and creative design, relying on the local technical knowledge of the Iranian Navy... and has been built with stealth capabilities," Rear-Admiral Alireza Sheikhi, head of the navy shipyards that built the destroyer, told Iranian state news agency IRNA.
Iran's navy has extended its reach in recent years, launching vessels in the Indian Ocean and the Gulf of Aden to protect Iranian ships from Somali pirates operating in the area.
Iran added the first domestically made destroyer to its fleet in 2010 in the Persian Gulf. Iran reportedly has five other destroyers.
On Thursday, Iran's navy announced the acquisition of two mini-submarines designed for operation in shallow waters such as the Persian Gulf, including one new sub and one overhauled one.
The chief of staff of the Iranian armed forces said in 2016 that Iran may seek to set up naval bases in Yemen or Syria in the future, raising the prospect of distant footholds perhaps being more valuable militarily to Tehran than nuclear technology.