An evangelical pastor and an imam joined dozens of faith leaders in prayer before signing a pledge denouncing religious bigotry.

Texas Pastor Bob Roberts and Virginia Imam Mohamed Magid signed the pledge at Washington National Cathedral, RNS reported.

"I love Muslims as much as I love Christians," said Pastor Bob Roberts, of Northwood Church in Keller, Texas, before leading a prayer at the "Beyond Tolerance" event. "Jesus, when you get hold of us, there's nobody we don't love."

The religious leaders from the Christian, Jewish and Muslim faiths called on the nation protect the rights of all believers.  PBS said those taking part called on politicians and public officials to oppose bigotry, hate, and discrimination against people of all faiths.

The pledge comes after several years that have witnessed a rise in attempts to denigrate other religions and deny religious freedom of many, especially Muslims. Faith leaders are increasingly concerned at the growth in hate speech, crimes and bullying directed against Muslims. There has been growing opposition to the building or expansion of mosques a series of initiatives aimed at discriminating against Muslim religious practice, the faith leaders believe.

Shoulder-to-Shoulder, who sponsored the event, issued a call on their website for US citizens "to treat each other with compassion and honesty, and to foster an ethical commitment to bedrock American values such as pluralism and religious freedom, mutuality and respect."

The pledge states: "Each of our religious traditions teaches that human beings have the opportunity and the obligation to build communities in which peace and mutual respect are core expressions of an ethical life. Our religions also teach us that we must stand up for the rights and freedoms of all members of the communities in which we live, including people of faith backgrounds distinct from our own. This vision of just treatment for all human beings is born of our religious faith and commitment to fundamental American values and is manifested through our support of the principle that religious freedom must be guaranteed to people of all faiths and of no faith."

The pledge comes soon after US presidential candidate Ben Carson said he did not think a devout Muslim could be president and as a new survey shows pastors are increasingly polarised about Islam.

Although a majority considers Islam dangerous, a small but increasing segment believes Islam is similar to Christianity, according to a new survey by Nashville-based LifeWay Research.

Two-thirds of Protestant pastors agree Christianity and Islam should seek to coexist in America.

Compared to five years ago, pastors are much more likely to describe Islam in favorable terms. Fifty percent say Islam promotes charity, up from 33 percent. Significant numbers also describe Islam as spiritually good

"To understand the data, you have to understand that Protestant pastors are not of one mind," said Ed Stetzer, executive director of LifeWay Research, "And minds are changing in more than one direction."