The United States on Thursday criticised a tough sentence for a Kazakh human rights activist handed down months ahead of Kazakhstan's chairmanship of a European human rights body.

A Kazakh court this week upheld a four-year prison sentence for human rights campaigner and government critic Yevgeny Zhovtis who was jailed for manslaughter after a road traffic accident in a trial rights groups say was flawed.

Kazakhstan's human rights record has come under scrutiny as the former Soviet republic prepares to chair the Organisation for Security and Cooperation in Europe (OSCE) next year.

Zhovtis hit a pedestrian on a highway in July causing his death. Zhovtis said he had not been able to prevent the accident and called the verdict politically motivated. Rights groups say his brief trial was unfair and did not allow him to mount a proper defence.

Zhovtis was not allowed to attend the appeal.

On Thursday, the US embassy in Kazakhstan noted "with concern" the appeals trial ruling.

"After the original trial in September, there were credible allegations of procedural flaws in that trial, and the appeal hearing failed to address those concerns," a statement said.

"We urge the government of Kazakhstan to pursue the upcoming procedural review of the case fully in accord with Kazakhstani law and its commitment to international judicial standards."

Western rights groups such as Human Rights Watch have said Zhovtis' case undermined Kazakhstan's credibility as the future leader of the OSCE, Europe's main security and human rights body.

The government has denied any political motivation behind the case and said the trial had taken place in line with the law.

(REUTERS)