“UK tries to blackmail Iran by taking our OWN money – illegally kept for more than 40 years – hostage in exchange for prisoners,” Araghchi wrote in a tweet on Saturday.
“This is never going to work,” he added.
“Time for UK to do right thing and stop letting US to sabotage humanitarian exchange,” the senior diplomat wrote, stressing that Iran and the UK still have a deal on the issue.
He had previously said in another tweet that the deal for release of 10 prisoners was concluded weeks ago, but the US officials had frozen it.