The head of a UN watchdog on Monday slammed Republicans over the US government shutdown, after a planned review of the country's rights record became the latest casualty of the budget impasse.

Nigel Rodley, a British expert who chairs the UN Human Rights Committee, lambasted the Republicans for allegedly ripping up their own history as they keep up their battle against President Barack Obama's signature health care law which aims to bridge the insurance gap for Americans.

"The political party of Abraham Lincoln that, in fire and blood ended slavery and gave freedom to millions of people of African descent, seemed now to have party members who thought that wealth did not just rhyme with health, but should also determine access to it," Rodley told the UN committee.

"To achieve its aim it had brought the government of the United States to a standstill and to the brink of defaulting on its national debt," he added.

Rodley lamented that his committee had had to postpone to March 2014 a review of the United States which had been scheduled this month.

"It was clear that the delegation from the United States was not unwilling to come, but was seriously unable to do so, for reasons that had been widely covered in the media," he said.

Like all UN member countries, the United States is meant to submit to periodic reviews of its rights record.

Meetings with delegations from Bolivia, Uruguay, Djibouti, Mauritania and Mozambique to assess their countries' records will go ahead as scheduled during the committee's current session.