Transcript for Nuclear Deal Sparks Celebrations in Iran But Backlash Here at Home
It's great to have you with us here order Tuesday night and we begin without historic deal with Iran sparking some celebrations in Iran but there has also been backlash here at home. It is a major victory for President Obama saying the deal is quote not built on trust it is built on verification. Tonight vowing to veto any efforts by congress to derail the deal. To millions of Americans it's an agreement few could've imagined those images for more than thirty years ago Americans blindfold held hostage at the US embassy in Tehran. Tonight decades later her rod eons of watching President Obama. ABC's Martha Raddatz is the only network reporter on the ground in Tehran but we begin tonight with ABC's chief foreign correspondent Terry Moran in Vienna. Where the deal was struck. Here they are those jubilant negotiators in the moment of triumph you can see it on John Kerry's face this moment has that a long time coming. And we have worked very hard to get here. Eighteen days in Vienna two years of high stakes diplomacy six years since President Obama first reached out directly to Iran's supreme leader. And 36 years since this. The 1979 hostage crisis Iran holding 52 American diplomats and citizens hostage. For 444. Long terrifying humiliating days. Today mr. Obama charting a new course this deal offers an opportunity to move. In a new direction. We should season. Iran now agrees to sharply cut back its nuclear program that has alarmed the world by. Dismantling two thirds of all its key nuclear machinery for ten years reducing its uranium stockpile by 98%. For fifteen years and submitting to continuous international monitoring and inspections and the US agrees to help Iran thrive. By ending those crippling economic sanctions recognizing Iran's right to even keep a peaceful nuclear program. And allowing a run over time to buy weapons even ballistic missiles this deal demonstrates that American diplomacy can bring about real and meaningful change. Critics pounced on the deal among the first and fiercest Israeli prime minister Netanyahu who called it a stunning historic mistake. But secretary Kerry shot back in a spirited interview with us today. The alternative is to what go to war immediately bomb them sanction them further well wait no you can't sanction them further. For decades the United States and Iran have been sworn enemies but you've got the sits here today that in new Ara has begun. For better or worse. David. Terry Moran in Vienna again tonight for us and ABC's chief global affairs correspondent Martha Raddatz the only American network reporter in Iran. Reporting tonight from one of those celebrations when word broke that the crippling US led economic sanctions will be lifted. Evening David coming to you from that very noisy streets of Tehran where spontaneous celebrations have been breaking. Outs and I. Celebrating the historic deal between America and its partners and Iran and all of these people know that those punishing sanctions. Will be lifted within the next couple of I'm saddened many civilians many of these people have suffered under those sanctions were what is even more remarkable is we're about two miles. From the former American embassy where in 1979. 52 Americans were held hostage. For a 144. Days. That event has changed the relationship between Iran and America or 35 years like here we are tonight David. Martha Raddatz in Tehran where some are calling this a victory tonight Martha thank you it is also in major political victory. For President Obama but tonight the fierce opposition already on Capitol Hill. Some members of congress vowing to fight it determined to knock down the deal. So we send Jon Karl straight to Capitol Hill where he heard an earful tonight about what they plan to do. Walking the halls of congress we found Republicans unified in opposing the Iran deal leading the charge freshman senator Tom cotton. Please do. Cotton tried to to rail the Iran negotiations back in March. By writing a letter signed by 47 Republican senators and sent to Iran's supreme leader. It warned the next president could undo any agreement with the stroke of a pan. Now he says he wants congress to kill the deal is what's the bottom line. Putting it out walk errors. Jon Carl back to the White House from Capitol Hill and John congress now has sixty days to vote on the steel. Yes and President Obama has said point blank today. That he will veto any effort by congress to derail this agreement. Republicans will need a lot of help from Democrats to override that veto I would be surprised to see that happen David. But I've got to tell you there is a lot of democratic concern tonight about this agreement all right Jon Karl Martha Raddatz Terry Moran thanks to you lawn.
This transcript has been automatically generated and may not be 100% accurate.