Mr Amano, who has previously said he would not travel to Tehran unless the matter was resolved, will be accompanied by his two most senior nuclear inspectors.
The agreement, which follows talks between the agency and iran in Vienna last week, will be seen as an encouraging sign ahead one next Wednesday’s negotiations in Baghdad.
There, negotiators will start work in earnest six weeks after the two sides held preliminary talks in Istanbul described by the United States as a “positive first step”. Western diplomats say that Iran has been forced to adopt a more constructive approach than it has in the past in response to the imposition of crippling EU and US sanctions this year.
But Israel remains sceptical with its prime minister, Benjamin Netanyahu, disparaging the forthcoming talks.
“It looks as though they see the talks as another opportunity to delay and deceive,” he said. “Iran is very good at playing this kind of chess game.
“I see no evidence whatsoever that Iran is serious about ending its nuclear programme.”
Similar comments made by Mr Netanyahu in recent months have been characterised as unhelpful by US officials.