The US military has detected no signs that Iran is preparing to close the strategic Strait of Hormuz despite tough rhetoric from Tehran, the Pentagon said Monday.

"We would have some knowledge of an intent to actively impede maritime traffic to the Strait of Hormuz. We don't see any active steps being taken by the Iranians to close the strait," press secretary George Little told reporters.

He called for a lowering of tensions after sharp language from Iran, which has warned it might prevent US warships from transiting the strait or shut the oil route if the West imposes stricter sanctions.

"We really do want to ratchet down the tensions surrounding the Strait of Hormuz. This is an important waterway for the region and for Iran itself," Little said.

The European Union has threatened a total ban on oil purchases from Iran over its nuclear program, which the West believes masks a drive to develop atomic weapons.

In response, Iran has threatened to close the vital Strait of Hormuz at the entrance to the Gulf -- through which 20 percent of the world's tanker-carried oil flows -- if its crude exports are blocked.

Iran's statements have helped send oil prices soaring in recent days.

Analysts say it is unlikely the Islamic Republic would make good on the threat as the country would face US-led military retaliation and severe economic consequences.

US Defense Secretary Leon Panetta and the military's top officer, General Martin Dempsey, reiterated Sunday that Washington would not tolerate any attempt to shut the strait.

Dempsey, chairman of the Joint Chiefs of Staff, acknowledged Iran could close the narrow waterway "for a period of time."

"We've described that as an intolerable act. And it's not just intolerable for us, it's intolerable to the world. But we would take action and reopen the straits," he said.