President Mahmoud Ahmadinejad said on Wednesday Iran had tested a missile that defense analysts say could hit Israel and U.S. bases in the Gulf, a move likely to fuel Western concern about Tehran's nuclear ambitions.
Ahmadinejad announced the test on the same day campaigning for the June 12 presidential election officially started.
A U.S. official said the test was a "step in the wrong direction".
One Western expert saw the missile test as Iran's response to the Israeli prime minister's U.S. visit this week.
Coming a day after Iran's supreme leader accused the United States of promoting terrorism, the test was a further disappointment for U.S. President Barack Obama's administration, which is seeking rapprochement with Iran after three decades of mutual mistrust.
"Iran just keeps going in the wrong direction. We want them to engage with us, to talk about how we can make the region more stable. This is just a step in the wrong direction," the U.S. official said.
U.S. patience is "not infinite", the official added. Read more.