State Department spokeswoman Victoria Nuland said the pair discussed Manama’s efforts to implement the recommendations of the Bahrain Independent Commission of Inquiry (BICI) into last year’s pro-democracy protests.
"Clinton noted the steps already taken to implement the recommendations, but expressed that much work remains to fully address ongoing human rights issues, including individual cases," Nuland said in a statement.
"She encouraged the Bahraini government to champion a clear process — in both word and action — that leads to meaningful institutional and political reforms that take into account the interests and aspirations of all Bahrainis," Nuland said.
King Hamad promised reforms after the independent commission probing Bahrain’s March 2011 crackdown on Shiite-led democracy protests reported in November that police had used "excessive force" and tortured detainees.
King Hamad commissioned the report to investigate allegations of government misconduct and human rights abuses against democracy activists and opposition figures.
Amnesty International says 60 people have been killed in Bahrain since the uprising began in mid-February 2011.
New York based Human Rights Watch said earlier this year that Bahrain’s "rulers have not fully carried out the key recommendations" of the inquiry into the "largely peaceful pro-democracy protests in February-March 2011."
"Clinton affirmed the long-standing commitment of the United States to a strong partnership with both the people and the government of Bahrain," Nuland added.
Bahrain is a key Gulf Arab ally as it serves as the headquarters for the US Navy’s Fifth Fleet.