MUSCAT, Oman — Vice President Cheney retained his tough stance against Iran today and said America is uncertain if Tehran has restarted the nuclear weaponization program that a U.S. intelligence report says it halted in 2003.

Speaking in Oman, an America-allied Arab monarchy and neighbor of Iran’s, Mr. Cheney told ABC News, “The important thing to keep in mind is the objective that we share with many of our friends in the region, and that is that a nuclear-armed Iran would be very destabilizing for the entire area.”

In December an intelligence report known as the National Intelligence Estimate concluded that Iran’s nuclear weapons development program was stopped in the fall of 2003 because of international pressure. The report, however, cautioned that Tehran continues to enrich uranium and still could develop a bomb between 2010 and 2015 if it decided to do so.

Critics of the Bush administration said the report should dampen any campaign for an American confrontation with Iran.

But Mr. Cheney that that while the NIE said Iran had a program to develop a nuclear warhead, it remains unclear if it has resumed that activity.

“What it (the NIE) says is that they have definitely had in the past a program to develop a nuclear warhead; that it would appear that they stopped that weaponization process in 2003. We don’t know whether or not they’ve restarted,” he said.

“What we do know is that they had then, and have now, a process by which they’re trying to enrich uranium, which is the key obstacle they’ve got to overcome in order to have a nuclear weapon,” he added. “They’ve been working at it for years.”

The vice president’s visit to Oman, part of a 10-day trip to the Middle East, fueled speculation that America was ratcheting up military pressure on Iran over its nuclear program. As a quiet American military ally, Oman allows America to use four air bases — including one just 50 miles from Iran — for refueling, logistics, and storage of pre-positioned military supplies.

Mr. Cheney denied that he’d stepped up his opposition to Iran’s nuclear policy.

“I’ve been pretty consistent over time about Iran,” he said. “I don’t think I’ve ratcheted up the rhetoric. I felt strongly for a long time, and a lot of us have, that Iran should not be allowed to develop nuclear weapons.”

Cheney officials said the vice president wanted to visit the sultanate to show American appreciation for its cooperation in fighting terrorism, but that Iran would be a top topic of discussion.

Before dining with Oman’s sultan, Qaboos bin Said, Mr. Cheney borrowed his 60-foot royal yacht and went fishing.

A Cheney spokeswoman said the vice president, his wife Lynne, and daughter, Liz, a former State Department official who is traveling with her father as a private citizen, headed out under sunny skies into the Gulf of Oman on “Kingfish I.” Mr. Cheney has had a personal relationship with the sultan going back to the time when the vice president was defense secretary, but the sultan did not go along on the fishing trip.