Human rights should not be violated, Pope Francis said on Thursday, denouncing the death penalty in Bahrain, in light of the first papal visit to the country, which also marks his second trip to the Gulf region.

The leader of the world's 1.3 billion Catholics is visiting Bahrain to promote dialogue between Christians and Muslims, but human rights groups and organizations had urged him to use the visit to speak out about the violations carried out by the state's monarchy. 

Pope Francis told his host, King Hamad bin Isa Al-Khalifa, that religious freedom should be "complete and not limited to freedom of worship."

Speaking a few weeks before the World Cup in the neighboring country Qatar, which has faced fierce scrutiny over its violation against the migrant workers, the Pope also demanded that "working conditions everywhere [be] safe and dignified".

"Much labor is in fact dehumanizing," he said. "This does not only entail a grave risk of social instability but constitutes a threat to human dignity."

It is vital that "fundamental human rights are not violated but promoted", Francis told the audience. 

"I think in the first place of the right to life, of the need to guarantee that right always, including for those being punished, whose lives should not be taken."

This comes after more than one message was sent to the Pope from Bahrain complaining about the injustice and oppression carried out by the authorities in the country, especially against prisoners of conscience.

The Pope's trip, which will last until Sunday, will include an open-air mass and will see him lead prayers for peace at a vast new cathedral.

However, the run-up to the visit has been marked by calls for him to put pressure on his hosts regarding the human rights violations.

Families of inmates on death row issued an open letter urging him to intervene.

"Our family members remain behind bars and at risk of execution despite the clear injustice of their convictions. Many of them were targeted because they took part in pro-democracy protests during the 'Arab Spring'," they wrote.

Human Rights Watch has accused Bahraini courts of issuing death sentences based on "manifestly unfair trials".

On Tuesday, human rights organizations urged the pope to publicly press Bahrain to "halt all executions, abolish the death penalty, and seriously investigate torture allegations and violations of the right to a fair trial".

These accusations have been rejected by the government spokesperson, who said Bahrain "does not tolerate discrimination" or prosecute anyone based on their religious or political beliefs.

Pope Francis, 85, has a knee problem and is consequently using a wheelchair; he boarded and disembarked from the airplane on an electronic platform.