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 Media 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. 

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U.S. vows to maintain pressure on Iran amid tension
Iran passes 3.67% uranium enrichment cap of 2015 deal

The United States may impose fresh sanctions on Iran, Hook also said, according to Twitter posts from Al Jazeera.  

Iran's President Hassan Rouhani said Wednesday Iran's increase in uranium enrichment was for peaceful aims, Iranian news agency Tasnim reported. 

He said Iran's decision to increase uranium enrichment would produce fuel for power plants and serve other peaceful aims, and that it was within the framework of Iran's 2015 nuclear deal with world powers. 

Rouhani also said Britain would face "consequences" over the seizure of an Iranian oil tanker. 

Read more: Iran calls UK's seizure of oil tanker 'threatening act'

"You (Britain) are the initiator of insecurity and you will realize the consequences later," said Rouhani after a cabinet meeting, according to Tasnim.