The United States is pursuing diplomatic and economic approaches to the unrest in Syria and "preparing military options should they become necessary" — steps also being taken with Iran, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said Friday in Hawaii.

Dempsey, the top uniformed member of the U.S. military, presided over a change of command at U.S. Pacific Command on Friday morning. He made the remark about Syria and Iran at a service members’ town hall meeting at Joint Base Pearl Harbor-Hickam.

Dempsey spoke to about 500 Navy and Air Force personnel at the Hickam officers club, fielding questions about cyberthreats, performing missions at a time of budget cuts, retirements and his feelings about Army Pfc. Bradley Manning, who is charged with turning over classified documents to Wiki­­Leaks.

Afterward, Dempsey told reporters that "Syria would be a greater challenge" for international military intervention than Libya.

"If you think about all the things that affect military operations, from size, population, geography, and then you go to military things, chemical and biological weapons, integrated air defense, conventional systems — yeah, it’s just a more challenging physical environment," Dempsey said.

"The question is not, Can we do it? Because the United States military is the most capable military force on the face of the planet. It’s, Should we? And then, would it best be done by us ourselves, or, in my personal view, we are always better when we operate with a coalition, because, generally speaking, it gives us greater credibility."

Operating with a coalition "always produces a better outcome, an enduring outcome," he said.

Sen. John McCain, R-Ariz., has called for U.S. airstrikes in Syria, where more than 7,500 people are estimated to have been killed in an ongoing government crackdown.

Dempsey said he’s at the point now "where we are looking at what I would describe as a commander’s estimate" — what are the potential missions and the "enemy order of battle" that would potentially make missions difficult to achieve, as well as looking at terrain and troop availability.

Dempsey, who met with the sailors and airmen and then was scheduled to head back to Washington, D.C., was asked about $487 billion in defense budget cuts over 10 years, and the possibility of another $1.2 trillion in federal budget cuts known as sequestration — half of which could be borne by the military.

"This $487 billion cut — we’ve been able to absorb it," Dempsey said. The size of the Marines and Army are shrinking with the cuts. "We lose capacity but not capability," Dempsey said.

If sequestration kicks in, "we may not be able to hold on to every capability, but we haven’t done the analysis yet," he said.

Dempsey said he is not "comfortable where we are" in cyberdefense, "but I can tell you, we’re pushing it."

He said the decision likely will be made to put "cyberheadquarters" at each of the combatant commands, including U.S. Pacific Command, and the military is seeking to add several thousand people into cyberwarfare jobs.

Dempsey, responding to a question about possible changes to retirement benefits, said the "going-in assumption" will be that anyone currently serving will have their retirement benefits grandfathered in.

The Joint Chiefs chairman also was asked about Manning, the alleged Wiki­­Leaks contributor, and whether Dempsey thought Manning should be viewed as a political prisoner, whistle-blower or traitor.

"We’re a nation of laws. He did violate the law," Dempsey said.