DUBAI (Reuters) - Iran's Supreme Leader Ayatollah Ali Khamenei said on Friday Tehran was in no rush for the United States to rejoin a 2015 nuclear deal, but that sanctions on the Islamic Republic must be lifted immediately.


"We are not insisting nor in a hurry for the U.S. to return to the deal," Khamenei said in live televised remarks. "But what is logical is our demand, is the lifting of the sanctions. These brutal sanctions must be lifted immediately."


Tensions have grown between Tehran and Washington since 2018, when U.S. President Donald Trump exited the deal between Iran and six world powers - which sought to limit Tehran’s nuclear program and prevent it developing atomic weapons - and reimposed sanctions that have crippled Iran's economy.


In retaliation, Tehran started gradually violating the accord.


Potentially complicating efforts by U.S. President-elect Joe Biden to rejoin the deal, Iran said on Monday it had resumed 20% uranium enrichment at its Fordow underground nuclear facility.


The U.N. nuclear watchdog confirmed that Iran had started the process of enriching uranium to 20% purity.


Tehran says it can quickly reverse its breaches if U.S. sanctions are removed. Biden, who takes office on Jan. 20, has said the United States will rejoin the deal “if Iran resumes strict compliance” with the pact.