The Senate panel that on Tuesday began questioning the admiral poised to become the top U.S. commander in the Middle East was particularly interested in one line of questions: Will his opinions be his own, and will he give them freely?

From the outset, the hearing focused greatly on Iraq, but also on many other areas of conflict in the Middle East, and how Adm. William Fallon would respond to those if he were confirmed to the post by the Senate.

Sen. John McCain of Arizona, the top-ranked Republican on the Senate Armed Services Committee, voiced his bitterness over the Iraq war handling and with former Bush administration officials, whom he said had not given the committee the unvarnished truth in the past.

McCain then gave stern advice to Fallon, 62, currently commander of U.S. forces in the Pacific. Fallon is nominated to take control of U.S. Central Command, a job that has been held by Army Gen. John Abizaid.

"I have to tell you, this committee did not get candid assessments in the past, and I view that with deep regret because I believe the American people and their representatives deserved better," McCain said.

"I want you to emphatically assure Sen. [Carl] Levin, the chairman, when he asks you that question, that you will, indeed, give us your candid and best assessment of the situation. Too often, administration officials came before this committee and the American people and painted a rosy picture that was not there," McCain said.

A few moments later, Levin arrived at the first set of standard questions about ethics and general cooperation. He paused at the question McCain mentioned.

"This is the question which Sen. McCain referred to," Levin said. "It means a great deal to us, and we're deadly serious about it. ... This one really becomes more and more important if you look at the recent history.

"Do you agree to give your personal views when asked before this committee to do so, even if those views differ from the administration in power?"

"Yes, sir. I do," Fallon said.

The hearing was expected to touch on a number of issues laid out in Levin, McCain and Fallon's opening statements, including the war in Iraq, Iranian influence and nuclear weapons proliferation in the Middle East, Al Qaeda's efforts to expand into Europe and Africa, and a number of other thorny topics.

The Central Command is responsible for U.S. military operations and relations in 27 countries stretching from the Horn of Africa, through the Middle East to Central Asia, including Afghanistan and Pakistan. Fallon said roughly 630 million people live in the region.

Fallon said Iraq would be his main point of focus.

"I believe the situation in Iraq can be turned around, but time is short. There are no guarantees. But you can depend on me for my best efforts," he said.

• Visit FOXNews.com's Iraq Center for more in-depth coverage.

Fallon said that he believed that U.S. military efforts need to change direction, but he also said that military efforts alone would not do the job in stabilizing Iraq. The comments were sure to hit home among the increasing number of both Republicans and Democrats on Capitol Hill who are — at the least — uneasy with the president's war plans.

Fallon said Iraq is "the top priority for CentCom attention. The situation in Iraq is serious, and clearly in need of new and different action."

He said that problems "will not be solved solely through military means," and that a comprehensive effort involving many government agencies will be necessary to improve Iraq's economy and reinvigorate the country's political system.

The Senate this week is expected to vote on a nonbinding resolution that would rebuke the Bush administration's Iraq policy, saying adding more military forces is "not in the national interest." Lawmakers have also offered other nonbinding resolutions criticizing the policy and calling for Iraqi benchmarks to be met.

Fallon also said that "we probably erred in our assessment" of the Iraqi government's ability to rebuild its society and establish a peaceful order after the overthrow of Iraqi dictator Saddam Hussein nearly four years ago.

Answering a question about what consequences there will be for Iraqis if they do not meet goals requested by U.S. forces, Fallon said it's important to show Iraqis the commitment won't be forever, but pressure could go too far.

"I believe that there will have to be firm understanding that we are not in an open-ended situation where we're just going to sit around and wait forever for things to happen. But I also believe it's not going to be particularly constructive right now to tape an edict of a number of actions, to give deadlines. I believe in giving them some time. How much time, I don't know, but time is running out," Fallon said.

In another portion of questioning, he said he planned to talk with U.S. diplomats and others "to get an assessment of what's realistic and what's practical" in Iraq.

"And maybe we ought to redefine the goals here a bit and do something that's more realistic in terms of getting some progress and then maybe take on the other things later," he added.

Asked by Levin whether the flow of additional U.S. troops would be tied to progress by the Iraqis on political and other commitments they made to Bush, Fallon said he had not yet studied the plans in detail, given his continuing responsibilities as Pacific Command chief.

"I'm surprised you don't have that understanding going in, frankly," Levin said.

Also Tuesday, the Senate Foreign Relations Committee began considering the nomination of John Negroponte, the first director of national intelligence, to become deputy secretary of state.

Both Fallon's and Negroponte's confirmations appeared locked up, despite heavy criticism — especially from Democrats — in both chambers of Congress about the president's Iraq war policy he outlined earlier this month, in which he intends to send 21,500 more troops, most into Baghdad, to secure and stabilize the country.

Last week the Senate approved, 81-0, Bush's nomination of Army Lt. Gen. David Petraeus to head the Iraq war. Petraeus would work alongside Fallon, who would oversee military operations throughout the region, including Afghanistan.

During Petraeus' Jan. 23 confirmation hearing, senators questioned him on how Bush's new strategy would work and whether Congress should weigh in with a resolution of disapproval. Petraeus said the situation in Iraq was "dire" but not hopeless.

Petraeus is to arrive in Baghdad to take over for Gen. George Casey as the top U.S. commander in Iraq next week, a defense official said Monday. Casey, tapped to become the next Army chief of staff, will face the Senate Armed Services Committee on Thursday.

Complete coverage is available in FOXNews.com's Iraq Center.

The Associated Press contributed to this report.