Updated 6:40 p.m. | The Senate’s top Pentagon appropriator told reporters Thursday he will be probing the Obama administration about legal authorities for the fight against Islamic State extremists, including in Syria.

“I have a lot of questions to ask about how they’re both interpreting the vote on the invasion of Iraq and the [authorization of use of military force] with Afghanistan,” Majority Whip Richard J. Durbin, D-Ill., said after a news conference where Senate Democratic leaders called for Congress to unite behind President Barack Obama as the nation confronts ISIS.

Durbin, who is chairman of the Defense Appropriations subcommittee, said after an all-senators closed briefing that he had gotten answers to questions about authority for the new military actions. Asked whether or not they were answers he wanted, the senator said the issue will be discussed at a Foreign Relations Committee hearing next week.

Secretary of State John Kerry is scheduled to testify at the Foreign Relations panel on Sept. 17, at 2:30 p.m.

Sen. Susan Collins, R-Maine, urged the Senate to give limited authority to the president to train and equip the vetted Syrian rebels and then the should Senate come back in October or in the lame duck to have a fuller debate “and consider on official authorization of use of military force.”

“I think that would be a far better way to proceed,” Collins said.

“This is a time . . . for Americans to close ranks and engage our adversaries as one united nation,” Senate Majority Leader Harry Reid, D-Nev., said at the news conference ahead of the briefing.

Administration officials briefed the Senate in a classified setting Thursday afternoon, where senators asked to ask many questions about the president’s strategy, which he outlined in a televised speech to the nation Wednesday night.

Sen. Jeanne Shaheen issued a statement after the briefing saying she would back efforts of Foreign Relations leadership to assemble a limited AUMF.

“While I recognize that the President has some existing authorities to target ISIL, I strongly believe he should come to Congress to get the authorization and bipartisan political support that will be required for the long-term fight to destroy these terrorists,” the New Hampshire Democrat said. “As a member of the Foreign Relations Committee, I support the Chairman and Ranking Member’s intention to draft a tailored Authorization for the Use of Military Force, and I intend to work with them in this effort.”

Earlier, Durbin also called on Congress to vote to provide the president with the ability to train and equip vetted Syrian rebels to fight ISIS, known as Title 10 authority, which Obama has requested.

“I think that Congress should definitely vote on the Title 10 aspect of this, and as for the other part of it, I’m waiting to get more information on the legal, constitutional questions,” Durbin said.

But it’s unclear if the House will include the Title 10 provision in the catch-all funding bill Congress must pass before adjourning to keep the government operating, or if Congress will pass it separately as a stand-alone bill. Some Republicans have suggested it would be a greater show of support for the president as a separate bill.

Reid said how the Title 10 provision is handled will be up to the House, which will consider the continuing resolution before the Senate. Reid added that he’s been in contact with Speaker John A. Boehner, R-Ohio, on the issue.

“That is a decision the House is going to have to make,” Reid said. “As I have indicated . . . we will wait for what the House is going to do. I have spoken to the speaker . . . we had a nice visit yesterday and he is moving towards trying to bring everybody together and I appreciate what he’s trying to do.”

House Appropriations Chairman Harold Rogers, R-Ky., said he “thinks” Title 10 authorization will likely be attached to the continuing resolution. A path being discussed, he said, would be for the stopgap to be brought up as is and then for Title 10 language to be added as an amendment on the floor, allowing for a separate vote on the issue.

Nevertheless, Reid said he was relatively confident both the Title 10 authority provision and the temporary spending package would pass the Congress before the end next week.

Durbin recommended the provision be included in the continuing resolution and argued a vote for a stop-gap spending bill including Title 10 authority would still clearly be a vote in favor of Obama’s foreign policy plan.

“People know what they’re voting on here. I do,” Durbin said. “If I want to make the argument, ‘Oh, it was stuck in the back of the bill, and I never got to that page,’ try to explain that back home. Folks will remember how you voted on that issue, and some will decide to vote no. That’s their decision.”

In a statement issued earlier Thursday, the Senate Appropriations chairwoman said there wouldn’t be any uncontrolled war spending.

“America needs to build a strong international coalition response to defeat ISIS using military, intelligence, financial and political means. Europe, the Arab States and other allies and partners must step up on all fronts,” Sen. Barbara A. Mikulski, D-Md., said. “Defeating ISIS will take time, but we cannot have an open-ended conflict. We must avoid the mistakes made following 9/11. There can be no blank checks and no proposals without real strategies connected to them.”

During the news conference, Durbin said it was too early to speculate whether the White House would need more funding to bring its ISIS plan to fruition.

“I think it’s just too soon to be speculating about the cost of this effort,” Durbin said.

Reid also urged caution. He sought to tamp down speculation, adding that this is the beginning of a journey that must be taken with sober deliberation. He also didn’t rule out a vote on a new authorization of military force; Senate Foreign Relations Chairman Robert Menendez, D-N.J., said he plans to draw one up following hearings.

“We are at the beginning of a little trek that is going to be taken and we have to get it right,” Reid said. “We have to be deliberate in what we do.”

Tamar Hallerman and Megan Scully contributed to this article.

Related:

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Menendez Drafting New Authorization for ISIS War

Rhetoric Aside, Signs of Bipartisanship After Obama ISIS Speech

What Obama Wants From Congress for ISIS War

Obama’s ISIS Speech Text

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