The US pulling out of the Iran nuclear deal is cause for enormous international concern, federal Labor has warned.
US President Donald Trump has threatened to pull out of a deal which lifts sanctions in exchange for Iran slowing nuclear research and allowing inspections.
"I would be very concerned by an unravelling of the Iran nuclear deal," Deputy Labor Leader Tanya Plibersek told reporters in Canberra on Tuesday.
"I would be very concerned about Iran re-engaging in a nuclear weapons program."
Ms Plibersek, opposition foreign affairs spokeswoman from 2013 to 2016, said inspections suggested Iran had been abiding by the terms of the deal.
"Anything that allowed them to reinvigorate their nuclear weapons program is an enormous international concern," she said.
To stay in the deal, the US must renew sanction waivers on Iran by May 12.
President Trump says he will reveal his decision at the White House on Tuesday.
British foreign secretary Boris Johnson, appearing on the US morning show Fox & Friends, said the president was right to call attention to the deal.
"But you could do that without throwing the baby out with the bath water," Mr Johnson said.
