Iran has sentenced the Nobel peace prize laureate Narges Mohammadi to more than seven more years in prison after she began a hunger strike, her supporters said Sunday, as Tehran cracks down on all dissent following nationwide protests and the deaths of thousands at the hands of security forces.

The new convictions against Mohammadi come as Iran tries to negotiate with the US over its nuclear programme to avert a military strike threatened by Donald Trump. Iran’s top diplomat said on Sunday that Tehran’s strength came from its ability to “say no to the great powers”, striking a maximalist position just after negotiations in Oman with the US.

Mohammadi’s supporters cited her lawyer, Mostafa Nili, who had spoken to her. Nili confirmed the sentence on X, saying it had been handed down on Saturday by a court in the city of Mashhad.

“She has been sentenced to six years in prison for ‘gathering and collusion’ and one and a half years for propaganda and two-year travel ban,” he wrote. Mohammadi had received another two years of internal exile to the city of Khosf, about 740km (460 miles) south-east of the capital, Tehran, the lawyer added.

Iran did not immediately acknowledge the sentence.

Supporters say Mohammadi has been on a hunger strike since 2 Februrary. She had been arrested in December at a memorial ceremony honouring Khosrow Alikordi, a 46-year-old Iranian lawyer and human rights advocate who had been based in Mashhad. Footage from the demonstration showed her shouting, demanding justice for Alikordi and others.

Supporters had warned for months before her December arrest that Mohammadi, 53, was at risk of being put back into prison after she received a furlough in December 2024 over medical concerns. While that was to be only three weeks, her time out of prison lengthened, possibly as activists and western powers pushed Iran to keep her free. She remained out even during the 12-day war in June between Iran and Israel.

Mohammadi kept up her activism with public protests and international media appearances, including even demonstrating at one point in front of Tehran’s notorious Evin prison, where she had been held. She had been serving 13 years and nine months on charges of collusion against state security and propaganda against Iran’s government.

She also had backed the nationwide protests sparked by the 2022 death of Mahsa Amini, which have seen women openly defy the government by not wearing the hijab.

Mohammadi suffered multiple heart attacks while imprisoned before undergoing emergency surgery in 2022, her supporters say. In late 2024 her lawyer revealed doctors had found she had a bone lesion that they feared could be cancerous, which was later removed.

“Considering her illnesses, it is expected that she will be temporarily released on bail so that she can receive treatment,” Nili wrote.

However, Iranian officials have been signalling a harder line against all dissent since the demonstrations.