CAIRO  Iran announced Wednesday that it had test-fired an improved version of its most advanced missile, one capable of reaching Israel and parts of Europe, a move that appeared aimed at discouraging a military attack on its nuclear sites and to defy Western pressure over its nuclear program.

But the Pentagon said the test, on Tuesday, did not reveal anything “particularly different” about Iran’s abilities.

“I’m not going to get into the particulars of what our intelligence shows other than to say I don’t think there was anything here that was particularly different than what we’ve seen in the past,” said Geoff Morrell, the Pentagon press secretary, Reuters reported.

Still, the announcement provoked immediate rebukes from the White House and leaders in Europe, and appeared likely to intensify pressure from the United States and other Western powers to impose tougher economic sanctions on Iran.