However, the two top cabinet members will be facing a skeptical audience that will demand a clear answer to a complicated question: How will an attack on Syria make a difference in the 2½-year civil war?
In another development, the UN refugee agency reported Tuesday the number of refugees fleeing Syria's violence has surpassed the 2 million mark — another tragic sign of a civil war that shows no sign of letting up.
Antonio Guterres, the head of the Office for the UN High Commissioner for Refugees, said Syria is hemorrhaging an average of almost 5,000 citizens a day across its borders, many of them with little more than the clothes they are wearing. Guterres said in a statement Tuesday that nearly 1.8 million of the refugees have fled in the past 12 months alone.
[CUSTOM"Syria has become the great tragedy of this century — a disgraceful humanitarian calamity with suffering and displacement unparalleled in recent history," he said. "The only solace is the humanity shown by the neighbouring countries in welcoming and saving the lives of so many refugees."
The agency's special envoy, Angelina Jolie, says "some neighbouring countries could be brought to the point of collapse" if the situation keeps deteriorating at its current pace.
]In Washington, the Democratic-led Senate is expected to approve U.S. military action, but there is stronger opposition in the House of Representatives, where even some Democrats appeared skeptical that attacks sought by President Barack Obama could help end the war in Syria.
"People are horrified by the pictures of people suffering and they genuinely want to help," James McGovern, a liberal Democrat representative from Massachusetts, said Monday. "But people have become — it's more than just war-weary, they've become skeptical of the effectiveness of these military involvements."
Though naval forces are in position to launch cruise missiles on Obama's order, no decision is likely until days after Congress returns from its summer recess on Sept. 9. In the interim, Obama is using the time to build his case in Congress.
Two leading Senate Republicans, John McCain of Arizona and Lindsey Graham of South Carolina, said Monday the administration must make a strong case for attacking Syria if he wants to win congressional backing for the operation.
In Europe, French President François Hollande emerged as the most vocal international leader calling for armed reprisals against the Bashar- al-Assad regime following the release of a report by France's spy services that laid the blame for the Aug. 21 attack squarely at the door of government forces.
However, Hollande has said France will not intervene alone in the civil war, which has so far resulted in 100,000 deaths and the displacement of a third of the country's population. Britain, Germany and Canada have already rejected an armed assault on Syrian government forces, leaving the French president struggling to build a coalition of partners.