Five rights groups yesterday called for United States Secretary of State John Kerry to use a visit to Phnom Penh this week to demand the Cambodian government stop persecuting political opponents and rights, environmental and trade union activists.

Kerry will arrive on Tuesday to meet with Prime Minister Hun Sen and Foreign Minister Hor Namhong in a bid to “strengthen” the countries bilateral and economic ties, as well as discuss the premier’s upcoming trip to the US.

An open letter published yesterday, released through human rights umbrella group International Federation for Human Rights (FIDH), said any such improvement in relations should be made “contingent” on the government’s progress in promoting democratic reforms and respect for human rights and fundamental freedoms.

“We urge you to demand an immediate end to the government’s acts of intimidation, judicial harassment, and violence against opposition officials and the immediate and unconditional release of all 17 opposition members and supporters who are currently detained or imprisoned,” stated the letter, signed by representatives of FIDH, Adhoc, Licadho, the Cambodian Center for Human Rights and the Asian Forum for Human Rights and Development.

Government representatives were unavailable yesterday. Ruling party spokesman Sok Eysan declined to comment.