Washington (CNN) -- Diplomacy remains the favored option as the U.S. grapples with how best to deal with Syria, but the U.S. military has drawn up plans to use if diplomacy fails.
Officials issued fresh reminders of its military alternatives this week as world outrage mounted over last week's massacre that left more than 100 people dead in the town of Houla.
"As you know, my job is to provide the commander-in-chief with options," said Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff. "I think the military option should be considered."
Actions under discussion include sending in troops to protect Syria's chemical and biological weapons and providing massive humanitarian assistance, according to a U.S. official and other officials in the region.
U.S., British, Jordanian and Israeli military officials have been discussing what to do if Syria falls apart, the sources say.
Mike Rogers, the chairman of the House Intelligence Committee, said the United States has the resources for robust action against President Bashar al-Assad's regime.
"There are certain things and capabilities that the United States has that can, in conjunction with our Arab League partners, could provide a tipping point so it would provide certain capabilities to units that we know who are trying to overthrow the Assad regime that we can vet, that we can test, that we can understand who completely that they are," the Michigan Republican said Wednesday.
Thousands have died since March 2011, when Syrian regime forces cracked down on peaceful protesters, prompting greater protest and inspiring an anti-government uprising as the regime clampdown persisted.
Thousands have died, and many fear a civil war if the country continues to deteriorate.
The United States and other world powers have been focused on diplomacy, not military options, for now. They have imposed economic sanctions on al-Assad's regime and pressed Russia to embrace an internationally accepted transition plan.
Washington is supporting U.N. and Arab League envoy Kofi Annan's peace initiative, which calls for a cease-fire and a political solution. It also backs the U.N. monitoring mission to ensure that the peace plan, accepted by the government and opposition groups, is being followed.
Deputy National Security Adviser Denis McDonough said the diplomatic push, informally called Plan A by government officials, is still the only game plan for Syria. The specter of military action, called Plan B, remains on the shelf -- but only for now.
"As it relates to what Plan B is for Syria, we're still on Plan A," McDonough said Wednesday at the U.S.-Islamic World Forum in Doha, Qatar, an event sponsored by the Brookings Institution. "The Annan Plan is part of Plan A, but we're not betting the farm on the Annan plan."
Conservatives in the U.S. Congress and some voices in the Arab world have called for arming the opposition.
In March, Sens. John McCain, Joe Lieberman and Lindsey Graham not only called for military aid to the Free Syrian Army, but urged, if requested by the opposition, a U.S.-led effort to protect civilian population centers with airstrikes.
Persian Gulf nations, including Qatar and Saudi Arabia, have talked of arming fledgling rebel forces against the much stronger Syrian military.
"The Syrian opposition are not going to be in a position to take and hold ground against the Syrian armed forces. What they can do is stage raids, provocations," said James Dobbins, head of international and security policy for the Rand Corp.
U.S. Ambassador to the U.N. Susan Rice told CNN on Wednesday that diplomats hope the Syrian government adheres to the Annan plan or the U.N. Security Council unifies in efforts to impose more pressure on al-Assad's regime.
"In either of those scenarios, there's still a potential for there to be a peaceful political resolution to this, which is what we seek," Rice said. "But if neither of those scenarios are possible, we're really facing the third scenario, which is the worst case, which is that the civil conflict intensifies, it engulfs the neighbors in the region, it takes on sectarian forms; it, effectively, becomes a proxy conflict between Syrian parties, but supported on the outside aggressively by others."
CNN's Joe Sterling contributed to this report.