Updated

Defense Secretary Leon Panetta, in an exclusive interview with Fox News, said that the stealth drone campaign along the Iran-Afghanistan border will "absolutely" continue despite the loss of a valuable and sophisticated drone to Iran.

The mysterious loss of the RQ-170 Sentinel drone has revealed not only that the U.S. was spying on Iran, but also that the program was being run from Shindad Air Base in western Afghanistan.

Panetta would not comment directly on what that drone was doing over Iran, but he said the U.S. military has no plans to halt the drone operation out of western Afghanistan.

"Those operations have to be protected in order to do the job and the mission that they're involved with," he said.

When asked if he would continue those missions as they have been conducted out of Afghanistan, he responded with one word: "Absolutely."

Panetta would not speculate about whether the Sentinel drone had been felled by a cyber attack or a high-tech jamming device.

"You can make all kinds of guesses at this point. Obviously there's nothing that you can rule out and nothing that you can rule in right now," he said.

President Obama said on Monday he would not comment on the situation beyond saying the U.S. has asked to Iranians to give it back. "We we will see how the Iranians respond," he said.

Panetta will travel later this week to Baghdad for a ceremony to mark the end of the U.S. war in Iraq. The secretary did not agree with the assessment of Prime Minister Nouri al-Maliki in Washington Monday suggesting Iranian interference in Iraq would disappear once all U.S. troops have gone home.

"I think you've got be very cautious about Iran and what they are doing," Panetta said. "I suspect in one way or another they are going to try to influence what happens there."

He added the U.S. will keep 40,000 troops in bases across the Gulf to counter any potential Iranian threat.

Meanwhile on Tuesday, a high-ranking Iranian official said Iran's military will practice sealing off the Strait of Hormuz, the world's most important oil transport channel. It's a provocative move that illustrates Iran's capability of disrupting the world's oil supply.

Pentagon spokesman Doug Wilson responding saying although he has no information on those specific exercises, the U.S. is "committed to the free and safe passage in international waters."

Anything that affects that, Wilson said, would be "detrimental."

Back in Kabul, the defense secretary will also be assessing how to heal the relationship with Pakistan after it closed border crossings and key supply routes in response to the Nov. 26 NATO air strike that killed 24 Pakistani troops.

Gen. John Allen, the top U.S. commander in Afghanistan, said that just before that incident, he went to see Pakistan's General Kayani for meetings he hoped would "bring the relationship back to a high level of coordination."

But in the aftermath of the incident on Nov. 26, "that has chilled to some extent," Allen said.