It comes as human rights organisation, Reprieve, also appeals to the US and British governments for urgent intervention on behalf of at least two Saudi Arabian juveniles and a young man with disabilities who face imminent execution.
They are all among 14 nationals who were transferred on Saturday from detention in Damman to Riyadh in what advocates say could be preparation for their executions.
Among the 14 are believed to be juveniles Mujtaba al-Sweikat and Salman Qureish, who were just 17-years-old in 2012 when they were alleged to have participated in protests, for which they were sentenced to death.
"This group includes two youths - one of whom, Mujtaba’a al-Sweikat, was at the airport coming to the United States to attend college when he was arrested," the federation said in a statement.
"People must have a right to speak and associate freely. Should these executions occur, Saudi Arabia should be considered a pariah nation by the world. We implore President Trump, as the standard-bearer for our great nation, to do everything in his power to stop the atrocities that may otherwise take place in Saudi Arabia.”
The Union's Michigan President, David Hecker, is urging the US President to use the capital from his recent trip to Saudi Arabia.
"President Trump displayed a close relationship with Saudi leaders during his recent trip to the kingdom. I urge him to use that relationship to plead with the new Saudi Crown Prince Mohammed bin Salman to halt the executions,” he said in the statement.
Twenty-three-year-old Munir al-Adam (below) is also believed to be among them. 
Maya Foa, Director of Reprieve, has grave concerns for the young man.
Mujtaba’a al-Sweikat,(left) Munir al-Adam (right) Source: Supplied
“Munir (al-Adam) was a disabled young man who was tortured so badly by the security forces he entirely lost the hearing on one ear. They are under imminent threat of beheading based on "confessions" extracted through torture," she said in a statement.
Reprieve is also appealing to the governments of the UK as well as the US.
"To carry out these executions would constitute an appalling breach of international law, and world leaders including President Trump, Secretary Tillerson and Prime Minister May should use their close ties to Saudi Arabia to make clear that these egregious abuses must end and the imminent executions must be halted,” the organisation said in a statement.
Others arrested while teenagers include Ali al-Nimr, nephew of Saudi Shiite cleric, Sheik Nimr al-Nimr, whose execution, together with 47 others in January 2016 sparked widespread international condemnation.
Ali al-Nimr has spent the past five years in prison, three of them on death row.
