Kerry is scheduled to visit Burma [also known as Myanmar] from August 8 to 10 to attend meetings of the Association of Southeast Asian Nations (ASEAN) and the ASEAN Regional Forum (ARF).
Many of the key indicators of human rights reform in Burma have stalled or are backsliding, Human Rights Watch said.
During the past year the number of political prisoners has risen with increased arbitrary arrests of peaceful protesters and prosecutions of journalists. Efforts to reform the justice system and enforce the rule of law have achieved little progress.
And the military has been involved in widespread abuses linked to land grabbing and continued fighting in ethnic minority areas. Human Rights Watch highlighted these and other issues in a letter to President Barack Obama in July.
''While the United States continues to spin a positive story about reforms in Burma, the reality is that the reform process has not only stopped but is going into reverse,'' said Brad Adams, Asia director at Human Rights Watch.
''Kerry should use his visit to deliver a clear and public message of deep concern about serious human rights problems, including continued persecution of the Rohingya, continued military abuses against ethnic groups, and the need for constitutional reform.''
The ASEAN meetings, which Burma chairs in 2014, precede the East Asia Summit in November in Naypyidaw, Burma's capital. World leaders, including US President Barack Obama, are expected to attend.
Kerry should strongly raise concerns about the persecution of the largely stateless Rohingya in Arakan [Rakhine] state, violence fomented by Buddhist extremists against the Muslim population, and new legislation infringing on the rights of religious minorities.
No one has been held responsible for the ''ethnic cleansing'' and crimes against humanity committed against the Rohingya in 2012, which caused more than 100,000 to flee the country and left another 140,000 displaced and living in dire conditions.
The government has not taken a public stand against Buddhist religious leaders whose statements and actions have fomented anti-Muslim violence and discrimination throughout the country.
Instead of using the law to help protect vulnerable religious groups, the government has endorsed several draft laws on religious conversion and interfaith marriage that would further isolate, intimidate, and discriminate against Muslims and other religious minorities.
Kerry should press the government to demonstrate genuine progress in ending the persecution of the Rohingya, preventing further sectarian violence, and abandoning discriminatory legislation.
''Optimism for Burma's reforms has been dealt a blow by the government's inaction in the face of rising violence against Muslims and its denial of basic rights to the long persecuted Rohingya,'' Adams said.
''Burma's government is playing with fire by allowing Buddhist extremists to dictate the boundaries of religious practice in the country.''
Kerry should also denounce continuing rights abuses by the Burmese army and opposition armed groups in ethnic minority areas and press for prosecution of those responsible, Human Rights Watch said.
Military abuses include killings, sexual violence, torture, and the use of child soldiers.
The Burmese military's business interests and those of its cronies have been responsible for land grabs resulting in mass displacement.
The government and military have blocked access by international aid and development agencies to ethnic minority areas devastated by decades of armed conflict, which lack basic education and health care.
Kerry should press for an end to war crimes in conflict areas, urge accountability for serious rights violations, call for the full participation of rights groups and women in all peace talks, and seek unfettered access by domestic and international aid agencies, Human Rights Watch said.
''The ongoing peace process with ethnic armed groups has not addressed the suffering of millions of ethnic minority people during decades of war,'' Adams said.
''While talks take place, the military still commits horrific abuses for which no one is held to account.''
Kerry should also raise concerns about faltering constitutional reforms. Burma's constitution contains numerous provisions that are undemocratic and violate fundamental rights, and should be amended or revoked before, not after, expected parliamentary elections in 2015.
Key provisions include the effective ban on a presidential candidacy by opposition leader Aung San Suu Kyi, the military's quota of 25 percent of the seats in parliament, and its powers to dismiss parliament and overrule civilian legislation.
The military's effective veto over constitutional amendments and behind the scenes oversight of the civilian government have ensured that reforms have stalled.
Kerry should make clear to the Burmese government that reforms need to be in place so that the Burmese people will be able to freely and fairly elect their leaders in 2015.
''Kerry should work with other donors and friends of the Burmese people to deliver a clear message to the country's leaders,'' Adams said.
''They need to be put on notice that Burma will lose US and international support if reforms do not continue.''