Iran poised for faster centrifuges as nuclear deal collapses

FILE - In this June 13, 2019 file photo, an oil tanker is on fire in the Gulf of Oman. The U.S. Navy is trying to put together a new coalition of nations to counter what it sees as a renewed maritime threat from Iran. Meanwhile, Iran finds itself backed into a corner and ready for a possible conflict. It stands poised on Friday, Sept. 6, 2019, to further break the terms of its 2015 nuclear deal with world powers. (AP Photo/ISNA, File)
FILE - In this June 13, 2019 file photo, an oil tanker is on fire in the Gulf of Oman. The U.S. Navy is trying to put together a new coalition of nations to counter what it sees as a renewed maritime threat from Iran. Meanwhile, Iran finds itself backed into a corner and ready for a possible conflict. It stands poised on Friday, Sept. 6, 2019, to further break the terms of its 2015 nuclear deal with world powers. (AP Photo/ISNA, File)

TEHRAN, Iran (AP) - Iran was poised Thursday to begin work on advanced centrifuges that will enrich uranium faster as the 2015 nuclear deal unravels further and a last-minute French proposal offering a $15-billion line of credit to compensate Iran for not being able to sell its crude oil abroad because of U.S. sanctions looked increasingly unlikely.

Meanwhile, Iran released seven crew members from a detained British-flagged oil tanker Stena Impero in a goodwill gesture and the mariners flew out of Iran, the ship's owner said.

The state-run IRNA news agency reported late Thursday that Iran will halt its commitments on research and development as its most recent step to move away from the 2015 nuclear deal with world powers. The report didn't elaborate and said further details would be announced later.

IRNA said the Foreign Ministry announced the move from a detail in a letter from Foreign Minister Mohammad Javad Zarif to EU foreign policy chief Federica Mogherini.

Iran has yet to say officially what exact steps it will take as a deadline it gave Europeans to salvage the deal is to expire Friday. However, centrifuges that speed uranium enrichment would further shorten the time Tehran would need to have enough material available to build a nuclear weapon - if it chose to do so.

Under the deal, which has steadily unraveled after President Donald Trump's unilateral withdrawal of the U.S. from the accord last year, experts thought Iran would need about a year to reach that point.

Iran's atomic energy agency was to make an announcement on Saturday detailing its next step, which President Hassan Rouhani described as highly significant, according to the semi-official Tasnim news agency and other Iranian media. The details would be unveiled at a news conference in Tehran, the reports said.

The U.S. has continued its effort to choke off Iran's crude oil sales abroad, a crucial source of government revenue. Iranian Foreign Minister Mohammad Javad Zarif, who continues a whirlwind global diplomatic tour, insisted his country will do everything it can to keep those sales going, though he described U.S. sanctions in an angry tweet Thursday as the equivalent of a "jail warden."

"We will sell our oil, one way or the other," Zarif told Russian broadcaster RT in a recently aired interview. "The United States will not be able to prevent that."

Tensions between Iran and the U.S. have been growing since Trump's pullout from the nuclear deal, which saw Tehran agree to limit its uranium enrichment in exchange for the lifting of economic sanctions. Trump subsequently re-imposed old sanctions on Iran and created new ones, going as far as targeting Iranian officials like Zarif and Iran's paramilitary Revolutionary Guard.