By Barbara Starr and Tom Cohen
WASHINGTON (CNN) -- Former Sen. Chuck Hagel addressed concerns of his critics on Thursday in the opening statement of his confirmation hearing to become President Barack Obama's next defense secretary.
The Vietnam veteran's statement to the Senate Armed Services Committee said he fully supported Obama administration policies on ending combat operations in Afghanistan next year, preventing Iran from obtaining a nuclear weapon, and ending the ban on gays openly serving in the military.
Some conservatives, including former Senate colleagues, oppose his nomination because of what they characterize as his questionable support for Israel and maintaining a strong military.
However, other prominent political figures, including former Sen. Sam Nunn, a respected defense expert who introduced Hagel at the hearing, strongly endorsed his nomination.
Despite the conservative campaign against him, Hagel was expected to win Senate confirmation to succeed Leon Panetta as Pentagon chief.
The Nebraska Republican's opening statement at the hearing responded directly to his critics.
"No one individual vote, quote, or statement defines me, my beliefs, or my record," Hagel said in the remarks, which were released ahead of time by his office.
"My overall worldview has never changed: that America has and must maintain the strongest military in the world; that we must lead the international community to confront threats and challenges together; and that we must use all tools of American power to protect our citizens and our interests. I believe, and always have, that America must engage -- not retreat -- in the world. My record is consistent on these points," he said.
On specific issues, Hagel's statement declared that he was "fully committed to the president's goal of preventing Iran from obtaining a nuclear weapon, and -- as I've said in the past -- all options must be on the table to achieve that goal."
"My policy is one of prevention, and not one of containment -- and the president has made clear that is the policy of our government," the statement said.
In opening the hearing, Armed Services Chairman Carl Levin, D-Michigan, said to Hagel that "your reassurance to me in my office that you support the Obama administration's strong stance against Iran is significant."
However, ranking Republican Sen. James Inhofe of Oklahoma said he would oppose Hagel's nomination because of what he called Hagel's past support for what Inhofe called policies that would appease U.S. enemies. In particular, Inhofe cited Hagel's backing of direct talks with Iran, an enemy of Israel.
Hagel's statement declared Israel as "our friend and ally", and pledged continued support to helping it maintain its military prowess in the region.
In addition, Hagel's statement said he would maintain "a modern, strong, safe, ready, and effective nuclear arsenal," adding that he was "committed to modernizing our nuclear arsenal."
Regarding the looming budget cuts to the military if Congress fails to find an alternative to mandated reductions, Hagel's statement said he would keep defense forces strong through better use of tax dollars.
"I am committed to effectively and efficiently using every single taxpayer dollar; to maintaining the strongest military in the world; and to working with Congress to ensure the department has the resources it needs -- and that the disposition of those resources is accountable," he said in the statement.
If confirmed, Hagel will be the first enlisted man to serve as defense secretary. He was a decorated Army sergeant in the Vietnam War.
On the eve of his hearing, Hagel received the endorsement of seven prominent veterans groups, including Veterans of Foreign Wars and the American Legion.
In its letter of endorsement, the Iraq and Afghanistan Veterans of America said of Hagel, "As a former enlisted soldier, Senator Hagel understands the challenges our troops and veterans face on a deeply personal level."
In preparation for the hearing, sources said, Hagel endured three "murder boards" in which staff peppered him with questions simulating a confirmation hearing. He also he met with 60 senators and has appointments to meet with more next week.
To date, only one Republican senator has endorsed his confirmation. The office of Sen. Thad Cochran confirmed to CNN that the Mississippi lawmaker plans to vote to confirm Hagel.
A plurality of Americans back Hagel's nomination to succeed Panetta.
According to a CNN/ORC International poll conducted January 14-15 and released two weeks ago, 48% of the public said the Senate should confirm Hagel, with 22% saying no and three in ten unsure.
The CNN poll indicated a partisan divide, with nearly two-thirds of Democrats saying Hagel should be confirmed. That number drops to 44% among independents and 32% among Republicans.
The CNN poll was in line with an ABC News/Washington Post poll that was conducted a few days earlier.