A U.S. official said the Pentagon has crafted military options for limited U.S. air strikes in Syria that would send a message to the regime of President Bashar al Assad not to continue using chemical weapons against its civilians. There has been no presidential decision to use the military options, and U.S. intelligence continues to investigate an apparent large-scale chemical weapons attack by the Assad regime this week that may have killed as many as 1,000 civilians.

The official said the military options developed for consideration by the White House are limited in scope and would be intended to "deter or prevent" the Assad regime from the further use of chemical weapons. The options are not intended to remove the Syrian president, who has tenaciously hung on to power as Syria's two-year civil war has raged on.

Traveling on a plane to Malaysia, Secretary of Defense Chuck Hagel confirmed to reporters that Obama had asked the Pentagon to provide military options in Syria in light of the reported use of chemical weapons against civilians by the civilian government.

"The Defense Department has responsibility to provide the president with options for all contingencies, and that requires positioning our forces, positioning our assets to be able to carry out different options, whatever options the president might choose," Hagel said, according to The Associated Press.

Potential targets include Syrian military or government command and control facilities as well as delivery systems for Syria's chemical weapons, namely artillery or missile launchers. Targeting Syrian chemical weapons depots carries the risk of unleashing chemicals into the atmosphere, which makes them less likely targets.

The limited scope military options would use "standoff" weapons, which would not require the U.S. to send jet fighters over Syrian airspace and risk their getting shot down by Syria's strong air defense system. The use of sea-launched Tomahawk cruise missiles is seen as the most likely option.

Another standoff option would involve fighter jets launching their munitions from outside Syrian airspace. This is a method that Israel has used to conduct several airstrikes into Syria this year without challenging Syria's air defenses.

There was discussion of the limited military options at Thursday's lengthy meeting of top National Security advisers at the White House. The options have not been formally presented to President Obama for him to decide on whether he will choose that course of action.

There are plans for a National Security Council meeting Saturday where Syria will once again be a topic of discussion.

The U.S. intelligence community is currently conducting an assessment of what happened in the Damascus suburbs this week that has left so many Syrian civilians dead after what appeared to be exposure to a chemical agent. The official says the intelligence assessment is still ongoing.

The U.S. Navy currently has four destroyers in the Mediterranean, each equipped with more than 90 Tomahawk cruise missiles. The USS Barry and USS Gravely are currently located in the eastern Mediterranean as part of the Navy's ballistic missile defense mission in the region.

The USS Mahan and USS Ramage are located in the central Mediterranean, the Ramage is replacing the Mahan as part of that same mission in the eastern Mediterranean.

A Defense official says the commander of U.S. Naval Forces Europe ordered that the Mahan temporarily remain in the Mediterranean as it returned home from its deployment as part of the ballistic missile mission.