Iran’s battered currency has risen from its December lows by almost 9 percent against the US dollar as signs of progress in Vienna nuclear talks have emerged.

The rial fell to around 305,000 against the US dollar in early December as prospects for an agreement over Iran’s nuclear program dimmed in Vienna. Tehran has been negotiating with world power since last April to revive the 2015 nuclear agreement (JCPOA) that limited its uranium enrichment in exchange for lifting international sanctions.

On Sunday the US dollar was trading at 278,000 rials in Tehran’s non-official currency exchanges which reflect the street value of the currency.

Since the United States withdrew from the agreement in 2018 and imposed its own sanctions, the rial began falling with little support, as Iran lost most of its oil exports. It fell from 34,000 in late 2017 to 305,000 one month ago against the dollar.

It is not clear if rial’s partial recovery is supported by government intervention in the market or is purely psychological due to more optimistic statements by diplomats that the Vienna talks are making headway. If an agreement is reached, most US economic sanctions will be lifted providing Tehran with desparately needed foreign currencies.