FRANKFURT: German Foreign Minister Heiko Maas urged all sides to show flexibility and pragmatism in talks about the Iranian nuclear deal which are due to resume later on Saturday afternoon.

"It is about flexibility and pragmatism from all participating parties," he told Reuters.

"Playing for time is in no-one's interest," he added.

The talks between Iran and world powers are aimed at reviving a 2015 nuclear deal that was abandoned three years later by then President Donald Trump, who reimposed sanctions that slashed Iran's oil exports.

Iran retaliated by violating the limits imposed under the accord on its nuclear programme. It now seeks an end to United States sanctions.

The new round of indirect talks is about how both sides might resume compliance with the old nuclear deal, formally called the Joint Comprehensive Plan of Action (JCPOA).

Under JCPOA, Iran limited its nuclear program to make it harder to obtain fissile material for atomic weapons in return for relief from US, EU and UN sanctions.

The US said on Thursday it had removed sanctions on three former Iranian officials and two companies that previously traded Iranian petrochemicals, a step one US official called routine but that could show US readiness to ease sanctions when justified.

The global oil market is watching the talks closely as additional oil volumes would weigh on prices.