In an article published on the Politico website, US Ambassador Samantha Power said diplomats from 193 member states of the United Nations are tracking the heated US congressional debate over the deal 'like they tracked the World Cup soccer pairings last year', Reuters reported.

'From this vantage point, I believe that rejecting this deal would significantly weaken our ability to achieve our broader foreign policy goals — most of which in 2015 require us to mobilize broad international coalitions,' Power wrote.

The White House says it is focused on building enough support for the Iran deal to keep Congress from 'spoiling' the agreement that was clinched between Iran, the United States and five major powers on July 14.

While President Barack Obama appears to have enough support among lawmakers to prevent Congress from overriding a veto should he need to use it, it is clear that most in the Republican-dominated legislature oppose the agreement.

Power said rejecting the agreement would hurt the United States more than it hurts Tehran.
'If the United States rejects this deal, we would instantly isolate ourselves from the countries that spent nearly two years working with American negotiators to hammer out its toughest provisions,' she said.

Power added, 'If we walk away, there is no diplomatic door number two.'

Rejecting the deal, she warned, would also likely undermine Washington's ability to use sanctions in other circumstances.

Critics of the deal in Washington have accused the Obama administration of giving Iran too much in exchange for too little. The Obama administration, however, has said that support for continued sanctions was waning and this was the best agreement that could be obtained.

Congress is expected to vote on the deal next month when its 60-day review period expires. US and European officials say that if the deal goes through most sanctions on Iran could be lifted next spring.