China prevented a human rights lawyer from travelling to the United States to receive an award for her work, she told AFP Thursday as she condemned the restriction on her freedom.

Authorities refused to provide Ni Yulan with a passport to attend a ceremony on Tuesday in Washington DC honouring "International Women of Courage", a day before Chinese President Xi Jinping arrived in the city for a nuclear summit.

The Public Security Bureau "would not let me leave", Ni said, adding that authorities informed her she was being stopped due to her involvement with more than 200 rights lawyers and activists detained by the government last summer.

"It is purely to limit my personal freedom," she said.

Ni is best known for her advocacy on behalf of Beijingers' property rights. She has been jailed twice and is paralysed from the waist down, a result she says of beatings received during her detention.

In a tongue-in-cheek letter posted online Wednesday, she thanked the "party and government" for making her award nomination possible, noting it was the direct result of an incident in 2014 when she says authorities held her in her apartment without food or water.

In desperation, she wrote, she reached out to "foreign diplomats" who brought supplies to her home and negotiated with China's foreign ministry on her behalf.

- 'Exceptional courage' -

Ni is one of a widening group of campaigners put under tightened control by Beijing as it seeks to tamp down activities that go against the party line.

She was one of 14 women from around the world recognised by the US State Department for "exceptional courage and leadership in advocating for peace, justice, human rights, gender equality and women's empowerment, often at great personal risk".

At the event, US Secretary of State John Kerry bemoaned the fact that China had refused to allow Ni to attend "despite repeated requests", and praised her "leadership in advocating for the rule of law and full, equal rights in China".

Ni was the only award-winner not present at the ceremony.

The US embassy in Beijing has "raised our concerns about Ni's passport refusal with the Chinese government", a spokesman told AFP.

Chinese foreign ministry spokesman Hong Lei said that Ni had "committed crimes in the past and was sentenced to prison".

"The US government has ulterior motives in giving this award to this person," he told a regular briefing, adding: "We oppose any foreign government's interference in China's domestic affairs under the pretext of human rights."

The Global Times, a newspaper linked to China's ruling Communist Party, quoted analysts as saying that the award was an attempt by Washington to "smear China's image and stir trouble".

Earlier this year, Beijing stopped journalist Yang Jisheng from travelling to the US to receive an award for his work documenting tens of millions of deaths from starvation during China's Great Leap Forward in the 1950s.

Government-affiliated academics have said his work is anti-China propaganda.