COLOMBO, Sri Lanka — A United Nations human rights panel urged Sri Lanka on Friday to repeal a constitutional amendment that critics say gives the country’s president too much power.

The United Nations Human Rights Committee criticized the amendment in its most recent report on how well Sri Lanka is complying with the International Covenant on Civil and Political Rights. The report said that the 18th Amendment, adopted by the government of President Mahinda Rajapaksa in September 2010, violated the principles of the covenant because it “empowers the president to dismiss or appoint members of the judiciary and other independent bodies.”

The committee said Mr. Rajapaksa’s firing of the country’s chief justice in January 2013 raised serious doubts about whether that power was consistent with basic principles of due process and judiciary independence.

The Sri Lankan government rejected the committee’s views and accused the panel of bias. Keheliya Rambukwella, the country’s media and information minister, told reporters on Friday in Colombo, the capital, that the committee had ignored much more significant threats to civil and political rights posed by the insurgents of the Liberation Tigers of Tamil Eelam, who fought the government for decades. In particular, he cited claims that the insurgents massacred 700 Sri Lankan police officers in 1990, at the height of the conflict.