Iran plans to return to the 2015 international nuclear deal under which it swore off the pursuit of nuclear weapons in exchange for eased sanctions - which it began to ignore after the US pulled out, the Iranian President said on Monday.

"[US President Donald] Trump and a few people holding grudges in Iran want to wipe the deal away ... but we have not allowed that and we will continue not to allow that," said Hassan Rowhani during a press conference.

Adhering to the terms of the deal could mean an end to sanctions and the country's economic crisis, he said, which means it is in the national interest.

"We shouldn't let unnecessary side topics like domestic quarrels lead us to lose sight of this main prize," said Rowhani.

Rowhani was referring to a law pushed through the legislature earlier this month by hardliners that would allow the government to ramp up uranium enrichment processes and block or even throw out international nuclear inspectors. The law contradicts multiple parts of the 2015 deal.

He noted that allowing the new law to take effect would not only poison relations with the International Atomic Energy Agency, but would make it harder to re-enter negotiations with the US once new president Joe Biden takes office next month.

"The new law in parliament was not smart," Rowhani said, noting that Iran needs solutions, not new problems.

Rowhani said he was convinced Iran could work out its differences with the US under Biden.

"As soon as the US returns to the deal, then we will do the same. ... It would be easy to do and could be done quickly."

The deal was signed by the last US administration, in which Biden was vice president.