Vice President Joe Biden met with Democratic senators to discuss the Iran talks on Wednesday, the White House said in a statement.
Biden emphasized that the goal of the talks is to prevent Iran from getting a nuclear weapon, and said that any relief from sanctions would be modest compared with the continuing overall impact of those sanctions.
The 12 lawmakers met for two hours with Biden, the White House said. Attendees included Senators Richard Blumenthal, Ben Cardin and Elizabeth Warren.
Major powers resumed talks in Geneva on Wednesday on a preliminary agreement to curb Iran's nuclear program. The United States has said it will be "very hard" to clinch a breakthrough deal this week.