A Tibetan poet and activist will not be able to receive a US government courage award in person after China denied her a passport for "national security" reasons, she said on Friday.

Tsering Woeser, an ethnic Tibetan writer, was one of nine women due to receive an "International Women of Courage" award at a glittering event in Washington on Friday, hosted by US Secretary of State John Kerry and First Lady Michelle Obama.

But Woeser, who has written on Tibetan issues for decades, said she was unable to leave China to receive the award, after being routinely denied a passport. "I applied in 2005, and last year," she said.

"Last year I was told: if I leave the country it will threaten national security," she said.

China's foreign ministry blasted the award as an attempt to "interfere in China's internal affairs", echoing comments made when jailed Chinese dissident Liu Xiaobo won the Nobel Peace Prize in 2010.

"The US giving such a person an award is a public support of her national splittist remarks and it is apparently violating the US commitment that Tibet is part of China," foreign ministry spokeswoman Hua Chunying said Friday.

But Woeser said that "for a rising power to respond this way doesn't make sense and shows its weakness".

Other writers who have vocally opposed policies advocated by China's ruling Communist party have also reported being denied passports.

China's government seeks to internally suppress reports on Tibetan calls for greater rights and autonomy from Beijing, and tensions in the region have heightened with more than 100 ethnic Tibetans setting themselves on fire since 2009.

Woeser said she would dedicate her award to self-immolators. "I've been writing about them, and feel sad about them," she said.

Beijing says that Tibetans enjoy religious freedom and have greatly benefited from economic development in the region in recent decades.