Republicans and Democrats appeared to rally behind President Barack Obama on Wednesday, echoing his warning that Syria’s use of chemical weapons against anti-government insurgents would be a “game-changer” requiring a more aggressive policy toward that country.

But Speaker John A. Boehner and senators in both parties made it clear that they want the White House to consult with Congress before taking action in Syria, particularly if it involves U.S. military intervention.

The lawmakers’ remarks came as Obama told a news conference in Jerusalem earlier Wednesday that if reports of the use of chemical weapons in Syria proved accurate, such a development would change U.S. policy and require action from the international community. But Obama, who has said in the past that Syria’s use of such weapons in the ongoing civil war would cross a red line, stressed that the United States and other nations were still trying to confirm the reports.

Idaho Republican Jim Risch, a member of Senate Intelligence Committee, said he expected to learn whether chemical weapons were used in Syria in short order.

“If the government has used chemical weapons and there is very clear proof of that, there’s going to be a lot of people believing that our strategy is going to have to change to some degree,” he said.

Asked what sort of policy changes to expect, he said: “At that point, almost everything is on the table for discussion.”

Some suggested the next steps could include U.S. military intervention to gain control of Syria’s chemical weapons stores.

Bob Corker of Tennessee, the ranking Republican on the Senate Foreign Relations Committee, also said that the use of chemical weapons, if confirmed, “changes the whole dynamic” of U.S. policy toward Syria. Up to now, Washington has sent only humanitarian and non-lethal assistance to the Syrian opposition.

“First we would need to ensure there are no more chemical weapons available to be used,” Corker said.” So we would need to learn how gain control over those compounds.” Asked if that could involve some form of U.S. military action, he said that was for the president and the military to decide.

“But the president has said it’s a red line, and it flies in the face of American sensibilities that a government would use weapons of mass destruction and chemical weapons against his own people,” he said.

The focus on a possible change in U.S. policy toward Syria comes as a result of a report by Syria’s state-run SANA news agency on Tuesday that said “a missile containing a chemical substance” was fired at a village by “terrorists” — the term it uses for rebels. The Syrian opposition denied the charge, accusing the government of using chemical weapons.

“I am deeply skeptical of any claim that, in fact, it was the opposition that used chemical weapons,” Obama told reporters. “The broader point is that once we establish the facts, I have made clear that the use of chemical weapons is a game changer.”

At a House hearing earlier Wednesday, Robert S. Ford, the U.S. ambassador to Syria, said there was no evidence to confirm the report.

War Powers

Members also made it clear Wednesday that they hope Obama has learned a lesson about getting Congress’ support for military actions — given the divisions that erupted over the 2011 U.S. intervention in Libya.

“I would hope that as the president is making his decision with what our reaction will be, that he will, in fact, consult with the bipartisan leaders in the Congress, something that didn’t happen before our involvement with Libya,” Boehner, R-Ohio, said.

Sen. Susan Collins, R-Maine, who attended a briefing on Syria yesterday, said the White House needs to say what its reaction will be, and, if the president wants to use military force, he should come to the Congress for authorization.

“I don’t think you can ignore chemical weapons nor the rise of al-Qaida in the region, but that doesn’t translate into ground troops on the ground. There are many other options. But I think the administration has an obligation to come to us with those options very soon, because it is the president himself who has repeatedly described this as the red line,” she said.

“If the red line has in fact been crossed, it seems to the president has an obligation to follow through on his threat. If he’s making idle threats, that’s the worst thing he can do,” Collins added.

Collins said the need for a congressional vote authorizing force would depend on what exactly the president proposes. Collins was among the senators who wanted a congressional vote authorizing force in Libya — a vote that never came in the Senate. In July 2011, the House voted against a resolution that would have authorized the U.S. participation in a NATO airstrike campaign that helped Libyan rebels oust dictator Muammar el-Qaddafi. Obama had argued he didn’t need Congress’ permission to participate in that coalition military action.

Collins acknowledged that if the president only wants to take more limited actions, such as arming the Syrian opposition without engaging the U.S. military, then he would not need to come to Congress.

Sen. Bernard Sanders, I-Vt., said if Obama wants to take military action, Congress should hold a vote authorizing it. “Yes, obviously there should be,” he said.

But Sanders said there is strong opposition in the country to any more wars.

“Today we acknowledged the 10th anniversary of the war in Iraq, the significant loss of life. … I don’t think the American people are anxious to get into another war.”

‘A Different Context’

Still, the prospect of chemical weapons use appears to have shifted congressional opinion on Syria. In addition to hawkish Republican senators like John McCain of Arizona and Lindsey Graham of South Carolina, some Democrats appear ready to consider a more active U.S. role.

Carl Levin, D-Mich., chairman of the Senate Armed Services Committee, said this week that it might be time for military intervention.

Others left little doubt that a change in Syria policy to a more aggressive posture was inevitable if the report proved true.

“The use of chemical weapons has to be regarded with the most serious and stern response and puts the entire conflict in a different context,” said Connecticut Democrat Richard Blumenthal, a member of Senate Armed Services Committee.

Several Republicans, meanwhile, made it clear that they blame the Obama administration for not intervening more actively earlier.

Sen. Saxby Chambliss, R-Ga., ranking member of the Intelligence Committee, said that if chemical weapons have been used, military action should be the U.S. response.

“Obviously you have to confirm the reports that have come out, but the president has said that if Assad uses chemical weapons that that is a red line,” Chambliss said. “There are a number of us who think we probably should have been more involved even at this point, so I would hope and I would expect that he would take much stronger action if that does prove to be the case, if they used chemical, or biological weapons.”

Asked what action he would recommend, Chambliss said, “That is for the military folks to tell us, but obviously military action of some sort, of some degree, I would hope would be proposed.”

Humberto Sanchez contributed to this report.