House Minority Leader Nancy Pelosi, D-Calif., said she is working to convince rank-and-file House Democrats to approve the nuclear deal with Iran, which she fully supports.

"Yes, yes," Pelosi said when asked whether she'll lobby her undecided caucus to back the plan. "I'm so proud of this. I'm already making sure, not lobbying but making sure, people have the answers to the questions they have. I made clear to them my own standing on this issue and why I think this is a good agreement. It's pretty exciting."

Pelosi started the briefing by proudly holding up the deal. "I've closely examined this document, and it will have my strong support," she said.

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Pelosi rejected criticisms that the agreement should have included a deal to free four Americans currently imprisoned by the Iranian government. Instead, she said the accord itself will benefit the prisoners.

"No, not, it would have been good, but no," Pelosi said, when asked about including the hostages as part of the agreement.

"This is a nuclear deal," Pelosi added. "This is a nuclear agreement. Since we have a nuclear negotiation and a nuclear agreement, a much brighter light is going to shine on the prisoners of conscience in Iran. This will shine a very bright light. I'm very optimistic."

Democrats in both chambers have expressed mostly tepid support for the deal, with some lawmakers far more skeptical than others that the agreement goes far enough to stop Iran from building a nuclear weapon.

Pelosi acknowledged "some of our members are in different places," and have questions about the deal, but she plans to work to convince them to vote in favor of it when it comes to the House floor after a 60-day review period. She said Democrats are in the "education phase" of considering the agreement.

The White House has stepped up efforts to sell the deal to Congress. Vice President Joe Biden met with Democrats in the House on Wednesday and is headed to the Senate today.

Pelosi called Biden's talk to Democrats "spectacular."

House Republicans will have the option of passing a resolution approving the deal, or disapproving the deal. The GOP is expected to push for a disapproval resolution, which is expected to pass, because it will only need a simple majority.

If that resolution can pass the Senate, it would then be vetoed by President Obama, which would send it back to both chambers. To override that veto, a two-thirds vote would be needed in the House and Senate.

For Pelosi, that means she needs to convince 146 Democrats to vote against the override. That means she could lose up to 42 Democrats and still ensure the safety of the Iran deal in the House.