A staff member removes the Iranian flag from the stage after a group picture with foreign ministers and representatives of the U.S., Iran, China, Russia, Britain, Germany, France and the European Union during the Iran nuclear talks at the Vienna International Center in Vienna, Austria July 14, 2015. To match Analysis USA-ELECTION/IRAN REUTERS/Carlos Barria/File Photo

DUBAI (Reuters) - The United States is seeking a Congress-approved agreement with Iran to replace the 2015 nuclear deal that President Donald Trump abandoned last year, the U.S. Special Representative for Iran Brian Hook told Al-Jazeera satellite television network.

The Trump administration has long argued that one of the flaws of the deal agreed under Trump’s predecessor Barack Obama is that it was not formally ratified by the U.S. Congress.

The United States may impose fresh sanctions on Iran, Hook also said, according to Twitter posts from Al Jazeera. He said the Gulf Arab states could be more effective in confronting Iran if they were united.

(The story is refiled to fix typo in first paragraph.)