In an open letter published Saturday by the Gulf Center for Human Rights (GCHR), signatories urged Obama "to press for the release of all detained human rights defenders across the Gulf region who are imprisoned solely due to their peaceful and legitimate human rights work".
"Instead of working with human rights defenders to combat extremism and build tolerant societies, authorities in the GCC countries have jailed dozens of them, in some cases for life, simply for exercising their right and duty to promote and protect human rights via freedoms of expression, association and peaceful assembly," it said.
The letter's signatories -- including Reporters Without Borders, Human Rights First and Front Line Defenders -- reminded Obama of his "promises made in 2011 to support popular movements for reform across the region".
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Obama is to attend a Gulf Cooperation Council (GCC) summit in Riyadh on April 21, which is to focus of the fight against jihadist groups and regional conflicts according to the White House.
The summit will follow one with Gulf allies in Camp David in May last year, which Saudi King Salman did not attend amid angst over Washington's efforts at the time to reach a nuclear deal with the kingdom's rival Iran.
Visiting Bahrain on Thursday, US Secretary of State John Kerry told authorities in the Sunni-ruled kingdom accused of discriminating against the country's Shiite majority that respect for human rights was "essential".
The GCC includes the Sunni-dominated monarchies of Saudi Arabia, the United Arab Emirates, Qatar, Kuwait, Oman and Bahrain.