ABOARD THE USS ENTERPRISE/BEIRUT: A U.S. aircraft carrier sailed through the Strait of Hormuz and into the Gulf without incident Sunday, a day after Iran backed away from an earlier threat to take action if an American carrier returned to the strategic waterway.

The carrier USS Abraham Lincoln completed a “regular and routine” passage through the strait, a critical gateway for the region’s oil exports, “as previously scheduled and without incident,” said Lieutenant Rebecca Rebarich, a spokeswoman for the U.S. Fifth Fleet.

U.S. Defense Secretary Leon Panetta had earlier told U.S. sailors aboard the vessel that tensions with Iran were an example of why massive ships are critical to their countries’ national security, vowing the U.S. carrier presence in the region would be maintained at full strength. Addressing about 1,700 sailors aboard the USS Enterprise, which after a half-century of service is about to embark on its final tour before being taken offline, Panetta said the United States will not cut America’s fleet of 11 aircraft carriers to help trim the budget deficit.

The Enterprise’s last deployment comes at a moment of heightened tensions with Iran, which has threatened to block the Strait of Hormuz, the world’s most important oil shipping lane. That’s something the United States says it will not allow.

“The president of the United States and all of us have decided that it is important for us to maintain our carrier presence at full strength. And that means we’ll be keeping 11 carriers in our force,” Panetta said, speaking about 100 nautical miles off the coast of the U.S. state of Georgia.

Iran’s Revolutionary Guard Corps Saturday played down the deployment of U.S. warships to the Gulf as part of routine activity, apparently backing away from previous warnings to Washington not to enter the area. “U.S. warships and military forces have been in the Persian Gulf and the Middle East region for many years and their decision in relation to the dispatch of a new warship is not a new issue and it should be interpreted as part of their permanent presence,” IRGC Deputy Commander Hossein Salami told the official IRNA news agency.

His comments were widely seen as an effort to reduce tensions that rose sharply this month when Iran threatened to block the Strait.

But in statements Sunday, the Commander of the Revolutionary Guards Navy, Ali Fadavi told ATY news, close to the Revolutionary Guards, that the “U.S. military navy presence is generally creating instability and danger in the region.”

There had been no U.S. aircraft carrier in the Gulf since the USS John C. Stennis left at the end of December. On Jan. 3, Iran told the Stennis not to return – an order interpreted by some observers in Iran and Washington as a blanket threat to any U.S. carriers.

Panetta said Sunday the crew were “going to a critical area of the world.”

Iran also announced it planned to hold naval exercises in the strait and the Gulf very soon.

Asked about Iran by one of the crew, Panetta said the United States would forge ahead with efforts to tighten sanctions isolating Iran over its nuclear program, which Iran insists is peaceful.

“But the most important way we make those messages clear is to show that we are prepared and strong and that we will have a presence in that part of the world. And that’s what this carrier is all about,” he said.