Speaking at a press conference, Mousavi said Asgari's case has been closed in America and if no issues or obstacles come up, he will return to the country in the next two or three days, according to IRNA.
Asgari was arrested in the United States in mid-2017. Back then, the FBI alleged the scientist had shared information about a project he had conducted in the US five years ago with his students.
However, the 59-year-old scientist from Tehran's Sharif University of Technology was acquitted in November.
The scientist recently contracted the new coronavirus after he repeatedly drew attention to his fragile health and called for his release from the “dirty” and “overcrowded” Louisiana jail facility, his lawyers told The Guardian.
In May, Iran’s Judiciary urged the US to immediately release the Iranian scientist.
If he returns to Iran, the scientist would become one of the few detainees held by either side not to have been released in a prisoner exchange.
Government spokesman Ali Rabiei said last month that Tehran had offered "some time ago" to exchange all Iranian and US prisoners but was waiting for a response from the US.
Iran in December freed Xiyue Wang, a US academic, in exchange for scientist Massoud Soleimani and said it was open to further swaps.