State Department spokeswoman Victoria Nuland expressed concern that "police, protesters, and bystanders have been killed" in clashes between demonstrators and Bahraini authorities over the past month.
There is tension in Bahrain -- home port on the Gulf of the US Fifth Fleet -- between supporters of the Sunni monarchy and members of the Shiite majority, tension that has led to recent protests and crackdowns on dissent.
Nuland said: "We continue to urge all Bahrainis to pursue their political objectives peacefully and the government of Bahrain to exercise restraint in responding to peaceful protests."
Nuland, issuing the statement on the one-year anniversary of a Bahrain Independent Commission of Inquiry (BICI) report into the violence, said the country needed to put more of its recommendations into effect. "Since the unrest began last year, the United States has urged the government of Bahrain to implement reforms and to address ongoing human rights concerns," she said.
"We will continue to encourage the Bahraini government and all segments of Bahraini society to create an environment conducive to political dialogue and reconciliation."
She added: "The Bahraini government can only achieve the more prosperous, stable, and secure Bahrain it seeks through the continuation of the reform efforts it has initiated and must now fully implement."
Nuland said Bahrain had taken "important steps" to implement the panel's findings, including allowing the visits by the International Red Cross to the country's prisons and issuing a new police code of conduct.
But she said there have been delays in ending "limits on freedom of expression and assembly" and in reforming "a political environment that has become increasingly inhospitable to reconciliation."