Iranian President Hassan Rouhani on Wednesday ordered all limits on nuclear research and development to be lifted, the third major step to scale down commitments to the 2015 nuclear accord with world powers.

During a televised speech, Rouhani said, “I, as of now, announce the third step,”, just as the United States announced that it was imposing sanctions against an oil shipping network with ties to Iran’s Revolutionary Guard”.

“The atomic energy organisation [of Iran] is ordered to immediately start whatever is needed in the field of research and development, and abandon all the commitments that were in place regarding research and development”(sic).

Earlier in July, Iran had abandoned two other nuclear commitments, to keep its stockpile of enriched uranium below 300-kilogrammes, and a 3.67 per cent cap on the purity of its uranium stocks.

The announcement came hours after Rouhani had threatened to take the step if Europe failed to provide a solution by Friday.

“Iran’s third step is of an extraordinarily significant nature,” Rouhani said earlier in the day, without detailing what that would entail.

The nuclear deal – agreed on by Iran, United Kingdom, China, France, Germany, Russia and the US – offered Tehran relief from many international sanctions in exchange for accepting curbs on its nuclear programme.

Since Washington pulled out of the deal last year and reimposed sanctions, Iran has insisted it wants to save the pact but has demanded the remaining signatories – especially the Europeans – provide additional economic support.

On Tuesday, the US imposed its first-ever sanctions against Iran’s space agency, accusing it of disguising a missile program.

Secretary of State Mike Pompeo said, “The United States will not allow Iran to use its space launch program as a cover to advance its ballistic missile program”.

The US also warned the “international scientific community that collaborating with Iran on space launch vehicles could contribute to its ballistic missile program.”

In response to the US, Iran said that its space program is aimed at building rockets to launch telecommunications satellites. Iran has fired two such satellites into orbit since 2013. But three other attempts this year have failed, including one rocket that blew up on the launch pad last week.

Meanwhile, Iran announced the release of seven of the 23 crew members of the seized British-flagged tanker Stena Impero on humanitarian grounds.