WASHINGTON — Lawmakers are making contingency plans for what happens if — or when — the nuclear accord with Iran falls apart.

Congress is out of town through the end of the month, but lawmakers are already weighing their options for how to address the deal with Iran, in which Tehran agrees to a six-month pause in its nuclear program in exchange for eased sanctions worth $7 billion. Lawmakers from both parties are skeptical the agreement will prod Tehran to give up its nuclear ambitions and say they will be waiting with even harsher punishment if Iran proves an untrustworthy partner.

The chairman of the Senate Foreign Relations Committee, Democrat Bob Menendez of New Jersey, says he is ready to work with colleagues on beefed up economic sanctions against Iran “should the talks falter or Iran fail to implement or breach the interim agreement.”

Arizona Sen. John McCain said he was “concerned this agreement could be a dangerous step that degrades our pressure on the Iranian regime without demonstrable actions on Iran’s part to end its pursuit of a nuclear weapons capability.”

The Republican said the situation “would be reminiscent of our experience over two decades with North Korea” and it is essential to keep the pressure on Iran.