The US will lift sanctions on Iran's civilian nuclear program reinstated by ex-President Donald Trump.

A senior US government spokesman said Friday that by reinstating a sanctions waiver Trump suspended in 2020, Washington wants to "facilitate" technical discussions in the final phase of the Vienna nuclear talks.

The reintroduction of the exemption should not be understood as a "concession to Iran" or as a signal "that we are close to an agreement," emphasized the government representative with a view to the nuclear negotiations in Vienna.

The revival of the international nuclear agreement with Iran is currently being negotiated in Vienna.

Western government representatives, including Federal Foreign Minister Annalena Baerbock (Greens), had recently warned urgently that the time window for a solution to the conflict with Iran was closing.

While core issues remain unresolved in the ongoing negotiations, Iran is "consistently expanding" its nuclear program, she warned.

The international nuclear agreement is intended to prevent Tehran from building nuclear weapons.

The United States withdrew from the agreement in 2018 under then-President Trump and again imposed massive sanctions on Tehran.

In 2020, the Trump administration also suspended a sanctions waiver, specifically affecting the Tehran research reactor and the Arak heavy-water reactor.

The reactor at Arak had been modified under the supervision of international controllers to make the production of plutonium for military use impossible.

Iran has also gradually withdrawn from the deal since the US pulled out of the nuclear deal.