The White House says it is confident final details on a deal to curb Iran's nuclear program can be worked out.
A White House spokesman said President Barack Obama spoke on April 3 with the four top leaders in the U.S. House of Representatives and the U.S. Senate to discuss the framework agreement announced on April 2 by negotiators in Switzerland.
"We feel good," White House spokesman Eric Schultz said. "There's a lot of work to be done, but we are confident we can get those details in place."
The agreement -- to curb Iran's nuclear program in exchange for lifting sanctions -- lays the groundwork for a final deal to be reached by a June 30 deadline.
Obama also discussed the deal with the leaders of Bahrain, Kuwait, Qatar, and the United Arab Emirates.
"He highlighted that nothing is agreed until everything is agreed," the White House said in a statement.
"He also reiterated the United States' enduring commitment to work with partners to address Iran's destabilizing activities in the region."
The White House also tried to ease Israeli concerns over the deal.
Prime Minister Benjamin Netanyahu said on April 3 the Jewish state demanded that any final agreement with Iran acknowledge his state's right to exist.
Asked about that demand, Schultz said Obama "would never sign onto a deal that he felt was a threat to the state of Israel."
Meanwhile, Iranian President Hassan Rohani, in a televised speech, hailed the framework as "a first step toward productive interactions with the world."
Schultz said he understood Tehran's need to sell the deal to Iranians but that the United States sees it as one focused on Iran's nuclear program.
"The concerns we have with Iran outside of the nuclear program remain just as vibrant...yesterday as they are today."
Rohani also said Tehran would fulfill its side of the agreement, and urged the West to do so as well.
"Everything we promised in the nuclear talks...we will remain loyal [to] and stand by our promises," Rohani said.
Iranians "do not seek to deceive" the international community, he added.
After eight days of negotiations, Iran and six world powers announced a series of understandings on April 2 on how to curb Iran's nuclear program.
They face a June 30 deadline for a final deal that is meant to cut significantly into Iran's bomb-capable technology while giving Tehran quick access to assets and markets blocked by international sanctions.
It marks the most significant step toward rapprochement between Washington and Tehran since the 1979 Iranian Revolution.
With reporting by Reuters and AP