WASHINGTON — Bilateral talks between the US and Iran regarding Iran’s nuclear program entered their second day Tuesday morning in Geneva, and while administration officials continued to push for a comprehensive agreement in time for a July 20 deadline, Congressional committees began to examine the potential implications of such a final deal.

With the first deadline for either concluding or extending the talks — as delineated in an earlier interim deal between Iran and world powers — looming less than six weeks away, the US negotiating team brought in veteran negotiators on Monday to help tie up loose ends.

State Department deputy spokeswoman Marie Harf said that the inclusion of Deputy Secretary of State William Burns and Jake Sullivan, the vice president’s national security adviser, was due to their history of negotiating with the Iranians, and their familiarity with the people involved in the talks.

“This is just another diplomatic avenue through which we are trying to test whether we can get this done by the 20th [of July],” Harf explained during a press briefing Monday. She added that while US officials were still comfortable with the talks’ current timeline, they knew that they “don’t have a lot of time left” and thus planned to step up diplomacy to encourage “tough choices.”

In Washington, Congress was also gearing up to renew its focus on the nuclear negotiations, with the House Foreign Affairs and Senate Foreign Relations Committees both holding hearings on Tehran this week. Stephen Rademaker, an assistant secretary of state during the Bush administration, and former International Atomic Energy Agency (IAEA) deputy director Olli Heinonen, were among those scheduled to testify in front of the House committee on Tuesday.

On Monday, Heinonen said that there was no single verification measure that could offer 100-percent assurances regarding Iran’s nuclear program. He emphasized that there were a number of measures that Iran must take in order to establish a reasonable verification regime, including being forced as part of an agreement to disclose all of its previously undeclared nuclear materials.

The former IAEA official said that he was confident in the effectiveness of the UN nuclear watchdog’s verification regime, and noted that Iran should be required to comply with remote monitoring at some of its most sensitive facilities, including at Fordo, Nantaz and Isfahan.

He also said that there should be an “escape clause” that would annul the agreement should Iran be caught “inching toward nuclear capabilities.”

In a statement last week announcing the hearing, the House committee’s chairman, Ed Royce (R-Calif), warned that “a nuclear Iran is the gravest national security threat facing the United States today.”

He said that during Tuesday’s hearing, committee members would examine “the requirements that would be needed for the United States and international inspectors to comprehensively verify Iran’s compliance with its nuclear commitments.” Royce emphasized that the hearing would be the first in a series of hearings in his committee concerning aspects of the Iranian nuclear program.

Two days later, the Senate committee will hold its own hearing on the regional implications of a comprehensive deal with Iran.

On Sunday, committee chairman Sen. Robert Menendez (D-NJ) warned that, should the administration seek to remove sanctions against Iran under a comprehensive deal, Congress would have to approve the removal of some of those sanctions. That could create a difficult situation for the administration, as past votes have demonstrated strong bipartisan for Iran sanctions in the Republican-controlled House of Representatives, as well as among most Republicans and a number of prominent Democrats in the Senate, including Menendez himself.

Still, Menendez did not say whether he foresaw a move to stymie any administration efforts to lift sanctions pending the signing of a comprehensive agreement with Iran.

Harf, the State Department spokeswoman, did not address questions about sanctions in her briefing Monday, but she did discuss relations with Iran, noting that even with a comprehensive agreement, the normalization of relations between the US and Iran would still be “very, very far away.”

President Barack Obama, she continued, has “said that many, many miles down the road, someday obviously we would like to have a different relationship with Iran, and if this could help play into that someday in the future, then fine.

“But even if we can get to a place where we get a comprehensive agreement, there are many things we still fundamentally disagree with the Iranian regime about what they’re doing, including in Syria, including with Hezbollah, including with human rights and women’s rights and support for terrorism,” Harf added. “Our concern over those things will in no way diminish if we can get to a nuclear deal.”