WASHINGTON: A bill to slap new sanctions on Iran has been delayed in the US Senate due to concerns about Iran's May presidential election, in which conservative hardliners hope to defeat moderate President Hassan Rouhani, US lawmakers said on Tuesday.

A group of Democratic and Republican senators introduced the bill in March seeking to impose tighter US sanctions on Iran over ballistic missile launches and other non-nuclear activities, echoing a harder line on Tehran espoused by Republican President Donald Trump.

But on Tuesday, the Republican chairman of the Senate Foreign Relations Committee, Bob Corker, said the bill would not move forward for now.

"We've got a Iran sanctions bill that has a number of co-sponsors that wasn't able to markup at present because of concerns about how the European Union might react and (Iranian) elections that are coming up," Corker said during a hearing on the EU as a US partner in dealings with Russia.

A markup is when a committee meets to debate legislation and to consider amendments.

Corker was a co-sponsor of the new sanctions bill, as were several other Democratic and Republican members of the Foreign Relations Committee.

As he has campaigned, Rouhani has called for greater individual freedoms and highlighted as a signature achievement the 2015 diplomatic breakthrough reached with the United States and other world powers, in which Iran curbed its nuclear program in exchange for relief from international sanctions.

The lawmakers who wrote the bill said it had been written specifically not to interfere with the nuclear accord.

But Iran has suggested that it would consider past proposed sanctions bills violations of the international pact reached during the administration of former US President Barack Obama, a Democrat.

Every Republican in the US Congress opposed the nuclear agreement. Trump criticized it while he campaigned for president in 2016, but his administration has so far said that it would seek to strictly enforce the pact rather than tear it up.-REUTERS