Former Secretary of State Hillary ClintonHillary Diane Rodham ClintonThe dangerous erosion of Democratic Party foundations The Hill's Morning Report - Presented by Facebook - Democrats see victory in a voting rights defeat Left laughs off floated changes to 2024 ticket MORE gave a cautious endorsement of the nuclear deal with Iran on Tuesday following a meeting on Capitol Hill with House Democrats.
"This is an important step in putting a lid on Iran's nuclear program," Clinton told reporters in an impromptu appearance before the cameras.
But, she emphasized, "We have to treat this as an ongoing enforcement effort."
Clinton said she will get a briefing later in the morning from national security advisers about the details of the deal.
Clinton said that there are still "concerns" about Iran's state sponsorship of terrorism and imprisonment of Americans on questionable charges.
"That bad behavior is something we have to address," Clinton said.
Democrats who met with Clinton said she strongly endorsed the nuclear accord during their meeting with her.
"She endorsed it — full-throated — and described her own role in helping to build the coalition … that led to this," Rep. Gerry Connolly (D-Va.) said leaving the closed-door meeting in the Capitol. "She laid out, 'Look, the alternative is unacceptable, and this is actually a good deal.' That's her words."
"She was not equivocal at all in her support for the agreement as she understands it," Connolly added.
Rep. Steve Israel (D-N.Y.), who voiced his own skepticism, also said Clinton is backing the agreement.
"She did say the core elements are worth supporting," Israel said. "She believes that we have an obligation to review all the details."
Reached Monday night, the historic deal is designed to block Iran from obtaining a nuclear weapon in exchange for the removal of international trade sanctions.
Liberal Democrats are praising the agreement as a big step in preventing a nuclear-armed Iran.
"With this agreement we have an opportunity to avert the unthinkable alternative of yet another war in the region and advance the broader goal of containing nuclear weapons globally," said Rep. Jim McGovern (D-Mass.).
Republicans, by contrast, wasted no time panning the deal. Speaker John Boehner (R-Ohio) is warning it will "fuel a nuclear arms race." And Rep. Steve Scalise (La.), the House Republican whip, is vowing to sink it in the House.
"We will fight hard to reject this deal with everything that we have," Scalise tweeted Tuesday morning.
Congress now has 60 days to review the accord.
Israel said Clinton's position on the issue will hold great sway among congressional Democrats ahead of that vote. He described her influence as second only to President Obama on the issue.
"There's no question that her opinion is critically important," he said.
One House Democrat, who spoke anonymously in order to discuss the private conversation, suggested Clinton's message to the Democrats carried stronger tones of support than her cautious public remarks.
"She was highlighting the positives within the report, and it sounded to me as if she would be more inclined to support it," the lawmaker said.
Clinton told the Democrats she'll be briefed more thoroughly on the agreement in a Tuesday morning conference call with White House officials and former secretaries of State.
"She'll probably have more to say after that," Connolly said.
Updated at 10:53 a.m.